Introduce a new regex for a special comment: howto?

[wimalopaan]

I tried to introduce a special comment for CPP-directives like

#include "bla.lua"

in lua.tmLanguage.json

.vscode-oss/extensions/sumneko.lua-2.5.3/syntaxes

But now luck with

```
				{
						"begin": "^\\s*#[a-z]+",
						"beginCaptures": {
							"0": {
								"name": "punctuation.definition.comment.lua"
							}
						},
						"end": "\\n",
						"name": "comment.line.double-dash.lua"
					},