(AB#61939) Add devcontainer (#9819)

This change adds a devcontainer definition to the repository. The
devcontainer can be used locally or as the backing definition for
a codespace and includes:

- PowerShell
- Git
- The GitHub CLI
- Vale
- All suggested VS Code extensions for the repository

This change enables us to move forward with advising contributors
to use GitHub Codespaces for their contributions to reduce the
friction for setting up their editor.

- Resolves AB#61939

Author: michaeltlombardi

Diff for: .devcontainer/Dockerfile

@@ -0,0 +1,4 @@
+FROM mcr.microsoft.com/devcontainers/base:ubuntu
+RUN wget https://github.com/errata-ai/vale/releases/download/v2.22.0/vale_2.22.0_Linux_64-bit.tar.gz && \
+    tar -xvzf vale_2.22.0_Linux_64-bit.tar.gz -C bin && \
+    export PATH=./bin:"$PATH"

Diff for: .devcontainer/devcontainer.json

@@ -0,0 +1,33 @@
+{
+	"build": {
+		"dockerfile": "Dockerfile"
+	},
+	"features": {
+		"ghcr.io/devcontainers/features/git:1": {},
+		"ghcr.io/devcontainers/features/github-cli:1": {},
+		"ghcr.io/devcontainers/features/powershell:1": {}
+	},
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"darkriszty.markdown-table-prettify",
+				"davidanson.vscode-markdownlint",
+				"docsmsft.docs-authoring-pack",
+				"eamodio.gitlens",
+				"errata-ai.vale-server",
+				"marvhen.reflow-markdown",
+				"ms-vscode.powershell",
+				"ms-vscode.wordcount",
+				"nhoizey.gremlins",
+				"redhat.vscode-yaml",
+				"shuworks.vscode-table-formatter",
+				"streetsidesoftware.code-spell-checker",
+				"tyriar.sort-lines",
+				"usernamehw.errorlens",
+				"wmaurer.change-case",
+				"Acrolinx.vscode-sidebar",
+				"yzane.markdown-pdf"
+			]
+		}
+	}
+}

Diff for: .gitattributes

@@ -9,6 +9,9 @@
 # Declare files that will always have CRLF line endings on checkout.
 *.sln text eol=crlf
 
+# Ensure devcontainer files are always LF
+.devcontainer/** eol=lf
+
 # Denote all files that are truly binary and should not be modified.
 *.png binary
 *.jpg binary