Switch to unclog

[thanethomson]

Closes: #1046

Description

I've updated unclog to be able to automatically resolve crates' names to their folders, such that you can add a .changelog entry with the following command:

# The "-c ibc" part is important
unclog add -c ibc improvements 123-some-issue

When building the changelog (unclog build -u to build unreleased changes), the output will look something like the following:

## Unreleased

### IMPROVEMENTS

- [ibc](modules)
  - An example issue

Right now unclog has support for Rust projects exclusively in the way we currently use our repos to facilitate a reverse lookup of a crate's folder (in this case the modules folder) from its crate name.

---

For contributor use:

• Updated the Unreleased section of CHANGELOG.md with the issue.
• If applicable: Unit tests written, added test to CI.
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Updated relevant documentation (docs/) and code comments.
• Re-reviewed Files changed in the Github PR explorer.

[adizere]

Thank you Thane, looking forward to trying this!