Add TOML highlighting

[lucas-x86]

Adds a TOML syntax highlighting definition (crates/lsh/definitions/toml.lsh) and a sample file under assets/highlighting-tests/. It applies to *.toml and Cargo.lock.

Test screenshot

Reproduce with cargo run -p lsh-bin -- render --input ./assets/highlighting-tests/toml.toml ./crates/lsh/definitions/

Note

• Literal strings are scanned without escape handling, so a trailing backslash (e.g. a Windows path 'C:\dir\') still terminates the string correctly.

[lucas-x86]

@microsoft-github-policy-service agree

[lhecker]

Thanks!