Introduce a new regex for a special comment: howto?

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"
},
```

Open .vscode-oss/extensions/sumneko.lua-2.5.3/syntaxes/lua.tmLanguage.json and inspect the syntax rules related to comments and the attempted begin/end pattern. Confirm that a directive such as #include "bla.lua" is recognized by the requested special-comment rule without affecting unrelated Lua syntax.

Written by the indexing model from the issue text.