feat(goslings): complete formula for goslings

## Summary

The `goslings` formula needs to be completed with proper values.

## Required Changes

1. Add a proper description
2. Set homepage URL
3. Remove all template comments
4. Set the correct license
5. Add proper `url` and `sha256` for a release
6. Update the `test` block with a real test

## References

- [Homebrew Formula Cookbook](https://docs.brew.sh/Formula-Cookbook)

Start by locating the goslings formula in the repository and review the Formula Cookbook reference. Complete its description, homepage, license, release URL, checksum, comments, and test block; it is done when the formula metadata is valid and the real test passes.

Written by the indexing model from the issue text.