docs: streamlined and organized DEVELOPMENT.md (#1735)

## PR Checklist

- [x] Addresses an existing open issue: fixes #1710
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Mostly re-applies changes from #1670.

💖

Author: JoshuaKGoldberg

.github/DEVELOPMENT.md

@@ -28,6 +28,12 @@ Add `--watch` to run the builder in a watch mode that continuously cleans and re
 pnpm build --watch
 ```
 
+### Built App Debugging
+
+This repository includes a [VS Code launch configuration](https://code.visualstudio.com/docs/editor/debugging) for debugging.
+To debug a `bin` app, add a breakpoint to your code, then run _Debug Program_ from the VS Code Debug panel (or press F5).
+VS Code will automatically run the `build` task in the background before running `./bin/index.js`.
+
 ## Formatting
 
 [Prettier](https://prettier.io) is used to format code.
@@ -58,7 +64,7 @@ For example, ESLint can be run with `--fix` to auto-fix some lint rule complaint
 pnpm run lint --fix
 ```
 
-Note that you'll likely need to run `pnpm build` before `pnpm lint` so that lint rules which check the file system can pick up on any built files.
+Note that you'll need to run `pnpm build` before `pnpm lint` so that lint rules which check the file system can pick up on any built files.
 
 ## Testing
 
@@ -99,19 +105,6 @@ Add `--watch` to keep the type checker running in a watch mode that updates the
 pnpm tsc --watch
 ```
 
-## Debugging
-
-This repository includes a [VS Code launch configuration](https://code.visualstudio.com/docs/editor/debugging) for debugging.
-Depending upon the type of usage, it can include debugging for unit tests _and_ for executable (or "bin") apps.
-
-### Unit Tests
-
-To debug a unit test, open a test file, then run _Debug Current Test File_ from the VS Code Debug panel (or press F5).
-
-### `bin` Apps
-
-To debug a `bin` app, add a breakpoint to your code, then run _Debug Program_ from the VS Code Debug panel (or press F5).
-
 ## Setup Scripts
 
 As described in the `README.md` file and `docs/`, this template repository comes with three scripts that can set up an existing or new repository.

script/__snapshots__/migrate-test-e2e.ts.snap

@@ -132,9 +132,7 @@ exports[`expected file changes > cspell.json 1`] = `
  		"markdownlintignore",
  		"mtfoley",
  		"npmignore",
--		"npmpackagejsonlintrc",
- 		"outro",
--		"packagejson",
+@@ ... @@
  		"tada",
  		"tseslint",
  		"tsup",

src/steps/writing/creation/dotGitHub/createDevelopment/index.test.ts

@@ -87,7 +87,7 @@ describe("createDevelopment", () => {
 
 			- \`pnpm lint\` ([ESLint](https://eslint.org) with [typescript-eslint](https://typescript-eslint.io)): Lints JavaScript and TypeScript source files
 			- \`pnpm lint:knip\` ([knip](https://github.com/webpro/knip)): Detects unused files, dependencies, and code exports
-			- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint): Checks Markdown source files
+			- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint)): Checks Markdown source files
 			- \`pnpm lint:packages\` ([pnpm dedupe --check](https://pnpm.io/cli/dedupe)): Checks for unnecessarily duplicated packages in the \`pnpm-lock.yml\` file
 			- \`pnpm lint:spelling\` ([cspell](https://cspell.org)): Spell checks across all source files
 
@@ -99,7 +99,7 @@ describe("createDevelopment", () => {
 			pnpm run lint --fix
 			\`\`\`
 
-			Note that you'll likely need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
+			Note that you'll need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
 
 			## Testing
 
@@ -216,7 +216,7 @@ describe("createDevelopment", () => {
 			pnpm run lint --fix
 			\`\`\`
 
-			Note that you'll likely need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
+			Note that you'll need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
 
 			## Testing
 
@@ -303,7 +303,17 @@ Def 456.
 
 			## Building
 
-			Will be removed.
+			Run [**tsup**](https://tsup.egoist.dev) locally to build source files from \`src/\` into output files in \`lib/\`:
+
+			\`\`\`shell
+			pnpm build
+			\`\`\`
+
+			Add \`--watch\` to run the builder in a watch mode that continuously cleans and recreates \`lib/\` as you save files:
+
+			\`\`\`shell
+			pnpm build --watch
+			\`\`\`
 
 			## Formatting
 
@@ -323,7 +333,7 @@ Def 456.
 
 			- \`pnpm lint\` ([ESLint](https://eslint.org) with [typescript-eslint](https://typescript-eslint.io)): Lints JavaScript and TypeScript source files
 			- \`pnpm lint:knip\` ([knip](https://github.com/webpro/knip)): Detects unused files, dependencies, and code exports
-			- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint): Checks Markdown source files
+			- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint)): Checks Markdown source files
 			- \`pnpm lint:packages\` ([pnpm dedupe --check](https://pnpm.io/cli/dedupe)): Checks for unnecessarily duplicated packages in the \`pnpm-lock.yml\` file
 			- \`pnpm lint:spelling\` ([cspell](https://cspell.org)): Spell checks across all source files
 
@@ -335,7 +345,7 @@ Def 456.
 			pnpm run lint --fix
 			\`\`\`
 
-			Note that you'll likely need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
+			Note that you'll need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.
 
 			## Testing
 

src/steps/writing/creation/dotGitHub/createDevelopment/index.ts

@@ -26,6 +26,11 @@ Add \`--watch\` to run the builder in a watch mode that continuously cleans and
 \`\`\`shell
 pnpm build --watch
 \`\`\``,
+		...(options.bin && {
+			"### Built App Debugging": `This repository includes a [VS Code launch configuration](https://code.visualstudio.com/docs/editor/debugging) for debugging.
+To debug a \`bin\` app, add a breakpoint to your code, then run _Debug Program_ from the VS Code Debug panel (or press F5).
+VS Code will automatically run the \`build\` task in the background before running \`${options.bin}\`.`,
+		}),
 		"## Formatting": `[Prettier](https://prettier.io) is used to format code.
 It should be applied automatically when you save files in VS Code or make a Git commit.
 
@@ -40,8 +45,7 @@ pnpm format --write
 pnpm run lint --fix
 \`\`\`
 
-Note that you'll likely need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.`,
-
+Note that you'll need to run \`pnpm build\` before \`pnpm lint\` so that lint rules which check the file system can pick up on any built files.`,
 		...(!options.excludeTests && {
 			"## Testing": `[Vitest](https://vitest.dev) is used for tests.
 You can run it locally on the command-line:
@@ -83,14 +87,35 @@ pnpm tsc --watch
 		Object.keys(newSections).map((key) => key.replace(/^#* /, "")),
 	]);
 
-	const preservedSections = Object.fromEntries(
-		splitIntoSections(existingContents).filter(([key]) => {
-			const keyText = key.replace(/^#* /, "");
-			return !newSectionHeadings.has(
-				headingAliases.get(keyText.toLowerCase()) ?? keyText,
-			);
-		}),
-	);
+	const existingSectionsSplit = splitIntoSections(existingContents);
+	const preservedSectionsSplit = existingSectionsSplit.filter(([key]) => {
+		const keyText = key.replace(/^#* /, "");
+		return !newSectionHeadings.has(
+			headingAliases.get(keyText.toLowerCase()) ?? keyText,
+		);
+	});
+	const preservedSections = Object.fromEntries(preservedSectionsSplit);
+
+	const sectionLines: string[] = [];
+	const seen = new Set<string>();
+
+	for (const sections of [newSections, preservedSections]) {
+		for (const heading in sections) {
+			if (seen.has(heading)) {
+				continue;
+			}
+
+			seen.add(heading);
+
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			const contents = sections[heading as keyof typeof sections]!;
+
+			sectionLines.push("");
+			sectionLines.push(heading);
+			sectionLines.push("");
+			sectionLines.push(contents);
+		}
+	}
 
 	const result = `# Development
 ${
@@ -111,14 +136,7 @@ pnpm install
 
 > This repository includes a list of suggested VS Code extensions.
 > It's a good idea to use [VS Code](https://code.visualstudio.com) and accept its suggestion to install them, as they'll help with development.
-
-${Object.entries({ ...newSections, ...preservedSections })
-	.map(
-		([heading, content]) => `${heading}
-
-${content}`,
-	)
-	.join("\n\n")}
+${sectionLines.join("\n")}
 `;
 
 	return result;
@@ -129,7 +147,7 @@ function createLintingSection(options: Options) {
 		!options.excludeLintKnip &&
 			`- \`pnpm lint:knip\` ([knip](https://github.com/webpro/knip)): Detects unused files, dependencies, and code exports`,
 		!options.excludeLintMd &&
-			`- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint): Checks Markdown source files`,
+			`- \`pnpm lint:md\` ([Markdownlint](https://github.com/DavidAnson/markdownlint)): Checks Markdown source files`,
 		!options.excludeLintPackages &&
 			`- \`pnpm lint:packages\` ([pnpm dedupe --check](https://pnpm.io/cli/dedupe)): Checks for unnecessarily duplicated packages in the \`pnpm-lock.yml\` file`,
 		!options.excludeLintSpelling &&