Add support for shared organization policies (#321)
Refactor configuration loading to use the go-githubapp/appconfig package. This mostly adds support for shared organization policies (in the .github repository by default), but should also make error messages more accurate.
It also changes the policy link in the details view to point to the resolved policy, instead of the local policy file.
Other Changes
- Update google/go-github to v38 (#326)
- Upgrade build dependencies