vscode/extensions/markdown/language-configuration.json

{
	"comments": {
		// symbols used for start and end a block comment. Remove this entry if your language does not support block comments
		"blockComment": [
			"<!--",
			"-->"
		]
	},
	// symbols used as brackets
	"brackets": [
		[
			"{",
			"}"
		],
		[
			"[",
			"]"
		],
		[
			"(",
			")"
		]
	],
	"autoClosingPairs": [
		[
			"{",
			"}"
		],
		[
			"[",
			"]"
		],
		[
			"(",
			")"
		]
	]
}