Add comments to switch statements

[andrewitsover]

This PR fixes #135657

[JacksonKearl]

Please see information at top of file:

vscode/extensions/csharp/syntaxes/csharp.tmLanguage.json

Lines 1 to 6 in 0aeced0

	{
	"information_for_contributors": [
	"This file has been converted from https://github.com/dotnet/csharp-tmLanguage/blob/master/grammars/csharp.tmLanguage",
	"If you want to provide a fix or improvement, please create a pull request against the original repository.",
	"Once accepted there, we are happy to receive an update request."
	],