Add support for Unity extensions (#5832)
Add support for Unity extensions (#5832)

* Add support for Unity extensions

Unity uses the extensions .jslib and .jspre to attach (pure) javascript code to WebGL applications

See: https://docs.unity3d.com/Manual/webgl-interactingwithbrowserscripting.html

* Alphabetical order
github/linguist,erkyrath/linguist,erkyrath/linguist,github/linguist,github/linguist,erkyrath/linguist,github/linguist,erkyrath/linguist