gleam: Improve indexing of HexDocs (#13787)

This PR improves the indexing of HexDocs content for Gleam packages.

We now index each of the modules in the package instead of just the
root.

Release Notes:

- N/A
98699a65c1Marshall Bowers committed on 7/3/2024, 4:57:08 PM· committed by GitHubparentf024fcf
2 files changedLine totals unavailable