Git Repo Config Support

gh-dash will now look for a .gh-dash.yml file if you run it from a git repo.
This allows you to define sections that are specific to this repo, and aren't suited for the global config.
Use cases include seeing PRs by teams you work closely with, issues sorted by reactions for your OSS project etc.

Changelog

• a5f99ce Update LICENSE.txt, fix license year
• 666aeba feat: read .gh-dash.yml file in repo root if exists