[EditorSyntax] switch to the better grammar!!

Grammar is copied from commit 8ec9066
https://github.com/PowerShell/EditorSyntax/blob/8ec90660044b1729d9724d83c37fec5d40d16186/PowerShellSyntax.tmLanguage

Merge pull request SublimeText#135 from SublimeText/dev

Dev

Merge pull request SublimeText#75 from vors/lightshow

Make tmLanguage file work with lightshow

Merge pull request SublimeText#37 from vors/master

Add Contributing section

Merge pull request SublimeText#12 from JPRuskin/patch-1

Update Support/Powershell.sublime-build