Added AGS (Adventure Game Studio) Script

Added support for Adventure Game Studio's scripting language. Currently the code is interpreted as ascii doc, causing it to be unreadable in github, for example:
https://github.com/pablofelt/Rat-s-Quest/blob/f114025e57c3ff780a9133a362ddb8ae82ca96ee/rquest/Digging.asc

There are quite a few public sources using the Scripting language: 
https://github.com/search?q=player+extension%3Aasc&type=Code&ref=searchresults