feat: multiline array support to the toml parser

[paval-shlyk]

Summary

This PR adds support for parsing multiline arrays in Cargo.toml, specifically addressing features lists that span multiple lines.

Relates to issue #77.

Changes

• Updated lua/crates/toml.lua logic to detect multiline array starts and accumulate content until the closing bracket.
• Refined regex patterns for single-line arrays to be stricter (removed ? optional check for closing bracket) to correctly fallback to the multiline parser when appropriate.
• Added tests in test/multiline_spec.lua and test/repro_spec.lua covering:
  • Multiline features in dependency sections.
  • Multiline features in inline tables.
  • Trailing commas and whitespace handling.

Notes

• I will be verifying this functionality through my own daily usage.
• Additional testing from the community is welcome!
• Note: This implementation was primarily "vibe coded" (as I don't use Lua on a primary basis). However, every change seems reasonable and the added tests pass.

[saecki]

Hey, thanks for this PR! I'll try to take a closer look and try this out this weekend.

I've noticed a few things right away. I don't think the case where inline-array items come after the multiline features array is handled. The type declaration of TomlCrateFeat and TomlFeature doesn't seem to be updated. The feature editing logic in edit.lua probably needs updating. Same for the popup code, which will also need to check for line numbers.

Somewhat related, with TOML 1.1 support landing in cargo, there is now also the possibility of multiline inline-tables. I'm not sure if that changes anything about this PR, just came to mind :)

[paval-shlyk]

I believed that everything would be much simpler)

Honestly, I didn't even know that multiline inline-tables had been added.

[saecki]

I believed that everything would be much simpler)

🫂

Honestly, I didn't even know that multiline inline-tables had been added.

Even if this PR "only" adds support for multi-line features, that would still be an improvement worth while :)