Add Wa Language

[chai2010]

This pull request adds support to Wa(凹语言) programming language.

Description

This pull request adds support to Wa(凹语言) programming language. Here are some relevant resources:

• Website(Chinese/中文): https://www.wa-lang.org/

• Website(English/英文): https://wa-lang.github.io/

• GitHub Organization: wa-lang

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*.wa
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/chai2010/brainfuck-wa
    • Sample license(s): Apache-2
  • I have included a syntax highlighting grammar: wa-lang/wa-tmLanguage
  • I have added a color
    • Hex value: #20b2aa
    • Rationale:
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

We can not accept this grammar. We can only accept grammars with one of these licences.

Please also ensure your samples are real world examples of the language in use. "Hello world" and similar learning examples are not examples of real usage.

[chai2010]

@lildude the wa grammar switch to Apache-2 licenese, and update the samples.

PTAL