Add the LiveCode Script language.

[torocruzand]

Description

Adding support for the LiveCode Script language. This language is an integral feature of LiveCode, a cross-platform application development environment.

Checklist:

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.LIVECODESCRIPT+SCRIPT
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample license(s):
      • MIT License
  • I have included a syntax highlighting grammar: https://github.com/Ferruslogic/vscode-livecodescript/
  • I have added a color
    • Hex value: #0C5BA5
    • Rationale: I chose this color because it is the color of the LiveCode icon.
  • I have updated the heuristics to distinguish my language from others using the same extension. Not required

[lildude]

The non-LiveCode script usage of this extension far outweighs the LiveCode Script usage. Linguist doesn't know of another language with this extension so all those files will be incorrectly identified.

You have two choices:

1. Identify at least one other language that uses that extension, that meets our usage requirements, and add it as part of this PR, along with a heuristic to distinguish the two, and removing the "hello world" example we expressly state will be rejected, or
2. Remove this extension and samples and users can then use an override until such time as someone does the first option.

[torocruzand]

Since the .lc extension is rarely used, I think it is better to eliminate it.