Cargo fmt & clippy, run CI on PR, spelling

[nyurik]

• Made a few changes similar to recent cleanup efforts with the geo repo

• spellchecking

• make clippy happier (there are still a few outstanding ones, todo in a separate PR)

• automatically run CI on PRs, not just push

• [x] I agree to follow the project's code of conduct.

• [ ] I added an entry to CHANGES.md if knowledge of this change could be valuable to users.

[michaelkirk]

bors r+

[bors[bot]]

Build succeeded:

• wkt