Add AngelScript to the list of supported languages

[aeris170]

As I can see from the way the languages/extensions are handled, this would be as easy to add another entry to the Dictionary in Constants.cs. I'd have done this myself and submitted a pull request but I couldn't understand how the language images are sent to discord. (Or where they are stored)

If you could provide me some background information on the language images, I can do the necessary changes and create a PR. Thank you.