feat: add logical-assignment-operators and operator-assignment lint rules (#662)

## PR Checklist

- [x] Addresses an existing open issue: fixes #646; fixes #647
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/template-typescript-node-package/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/template-typescript-node-package/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Enables the two rules.

Author: JoshuaKGoldberg

.eslintrc.cjs

@@ -39,6 +39,12 @@ module.exports = {
 			rules: {
 				// These off-by-default rules work well for this repo and we like them on.
 				"jsdoc/informative-docs": "error",
+				"logical-assignment-operators": [
+					"error",
+					"always",
+					{ enforceForIfStatements: true },
+				],
+				"operator-assignment": "error",
 
 				// These on-by-default rules don't work well for this repo and we like them off.
 				"jsdoc/require-jsdoc": "off",