chore: remove cosign.pub

feat: add reviewer/author mode (#1)

These modes are catered towards browsing PRs that are to be
reviewed or are authored by the logged in user.

fix: formatting in the review comments viewport

fix: show correct timeline items for first PR in list

+fix rendering of review comments (lipgloss seems to mess up rendering
of the viewport); will come back to this

feat: ask for repo on startup