feat: supports PHP

[XpycT]

• Stop words support
• Repository context support
• Update documentation / changelog

[wsxiaoys]

Hi,

I've revert this PR due to following error:

SET TABBY ROOT: '/var/folders/gd/3gkhr4g50zbf_zcpf00vmvfr0000gn/T/rstest'
thread 'tests::end_to_end' panicked at 'called `Result::unwrap()` on an `Err` value: InvalidCapture("module")', crates/tabby-scheduler/src/dataset.rs:282:22

It seems the query provided in tree-sitter-php is invalid.