- [Batch] Fix that using "::" as comments sometimes failed
- [html] Tabs give 2 spaces by default
- [JS] Tabs give 2 spaces by default; Allow comments to be inline with code.
- [Sh] Also highlight PKGBUILD; Fix `${v%tail}` not highlighted; Use shellcheck as linter
Duplicate syntax definition names may cause problems.
Since nano comes with predefined all-lowercase syntax definitions,
we use uppercase letters everywhere to reduce the risk of future conflicts