A bunch of requests

Here are my requests :)

Missing keywords : [a66ed65 ](https://github.com/ozlerhakan/AsciidocFX/commit/a66ed650485fc1cb621bb24a5a9554238f94c722)

A new shortcut for generating source block based on X language ( src.X or src,X = [src,X] ): [0c20f71](https://github.com/rahmanusta/AsciidocFX/commit/0c20f712df53b41da3561500884a4aa9db913a34)

Ctrl + W lets us save and close the current tab : [fe69fb7](https://github.com/ozlerhakan/AsciidocFX/commit/fe69fb70a22d68385bb6f2be5e094525400bd0c9)