This generalizes and cleans up the linter API so that it can be used in
other Doom projects (or CLI commands, like our WIP changelog generator).
Besides that, our git's commit conventions saw two changes:
- A new 'Amend' keyword, for indicating a commit corrects an earlier,
recent one. This should be used to omit (or merge) commits in the eyes
of the changelog generator.
- Trailers must now follow the 'KEY: VALUE' format, which is supported
OOTB by 'git interpret-trailers' and makes scraping them much eacher.
Before, omitting the colon was mandatory, this is no longer the case.
Other highlights:
- For linter rules: replaced :footer and :refs keys with :trailers (a
string->string alist). Invalid trailers will be left in BODY's tail.
- Added a linter for colon delimiters in commit trailers (along with
other formatting checks, like capitalization and one-per-line checks).
e4aecd1a5a