ci: add pr title format validation

[voxpelli]

What is the purpose of this pull request?

To assist #508 / #506 by ensuring that PR-title's are always valid conventional commit format before merging

What changes did you make? (Give an overview)

Added a pinned mtfoley/pr-compliance-action similar to what I use at eg. neostandard: https://github.com/neostandard/neostandard/blob/main/.github/workflows/compliance.yml

[scagood]

This may be better as a branch ruleset :thinking:

Then again, I dont know if this org is an 'Enterprise' org on github?

(This should be the link) https://github.com/eslint-community/eslint-plugin-promise/settings/rules/new?target=branch

Eg here is one in one of my repos:

[voxpelli]

@scagood I believe that's only enforced in enterprise organizations

[voxpelli]

I added it to the ruleset now, but yeah, not enforced :)