Update VS Code configuration (#38710)

* Enable auto-formatting of PHP files

* Add recommended VS Code extensions

* Add comments

.vscode/extensions.json

@@ -0,0 +1,14 @@
+{
+	/**
+	 * List of recommended extensions to use for this workspace.
+	 * The identifier of an extension is always `${publisher}.${name}`,
+	 * which is a part of the URL, e.g. https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint
+	 * You can view these extensions using the command `Extensions: Show Recommended Extensions`.
+	 */
+	"recommendations": [
+		"bmewburn.vscode-intelephense-client", // PHP Intelephense
+		"dbaeumer.vscode-eslint", // ESLint
+		"esbenp.prettier-vscode", // Prettier - Code formatter
+		"obliviousharmony.vscode-php-codesniffer" // PHP_CodeSniffer
+	]
+}

.vscode/settings.dist.jsonc

@@ -37,6 +37,16 @@
 		"**/jetpack_vendor/**",
 		"**/vendor/**"
 	],
+	// Custom settings for PHP files.
+	"[php]": {
+		// Ensure that PHP files are formatted with PHPCS.
+		"editor.formatOnSave": true,
+		"editor.defaultFormatter": "obliviousharmony.vscode-php-codesniffer"
+	},
+	// Run Code Actions for the editor.
+	"editor.codeActionsOnSave": {
+		"source.fixAll": "explicit"
+	},
 	// Use this wp-prettier from this path.
 	"prettier.prettierPath": "tools/js-tools/node_modules/prettier/index.cjs"
 }