New commitfest app release on August 19th

Thanks to the Claude Code AI tool I was able to get some boring
cleanup done on the CF app in not that much time. I'll release all of
it on August 19th.

List of the changes:
- Update to Bootstrap 5 for more modern visual look and better default
contrast of a bunch of UI elements.
- Add a navigation bar at the top of the page, including a "Contribute
on GitHub" button which links to the CF app repo.
- Move the dashboard to the homepage under the list of commitfests.
- Much better tag selector, which shows the tag descriptions and
colors. (descriptions are also searchable).
- Bugfix where draft patches would show in the wrong section in the
personal dashboard
- Nicer sorting icons for the commitfest columns (exact icon depends
on the column)
- Show Search/Filter options by default
- Improved the typography of date ranges by using an en-dash\