Created Luau

[Didward]

Luau (lowercase u, /ˈlu.aʊ/) is a fast, small, safe, gradually typed embeddable scripting language derived from Lua.

Adding a language

• [x] The code displays "Hello World" (tio.run may help for testing)
• [ ] I have updated the readme to include the new language
• [ ] I have incremented the language count in the readme
• [x] I have no association with the language
• [x] There are no copyright issues with this code
• [x] The language has not been added prior to this pull request

Link to programming language: https://luau-lang.org/

[Didward]

Forgot to add file extension 😅

[MrBrain295]

You need to update the readme.

[gnuhead-chieb]

ping:@MrBrain295