Whitelist injectionSelector in grammars

[pchaigno]

injectionSelector is an (undocumented?) key for Atom. See cdibbs/language-jison#17 for details.

/cc @vmg

[Alhadis]

Confirmed. I've written many grammars that make use of this property, because the syntax of TextMate's "normal" injection selectors is frigging impossible to figure out. 👍

[pchaigno]

@Alhadis Do you know if it's documented anywhere?

[Alhadis]

Nowhere officially, no. But there are wayyy too many parts of the TextMate grammar system that suffer from sketchy documentation. 😕

For example, there's also a little known property called matchEndFirst that (too my knowledge) has only ever been used by the original Perl grammar. It's never been documented anywhere.