Add static site to view the data

[egeakman]

Hey!

This adds a static website to be hosted on GH pages. Some of the features:

• iCal file served as conferences.ics, so folks can subscribe to the URL and get updates, every time a new commit is pushed to main
• filtering, search, and sort options
• option to add single event to different calendars
• option to export multiple events as iCal
• looks nice 🙂
• can work locally with just Python: python generate_conferences.py && python -m http.server
• also serves conferences.json, so can be used as a direct data source too

Also, one thing that could be done is to have a calendar view, which would be great if someone has the time to implement it!

Closes #89

[egeakman]

We should also add a notice at the top of the page (to encourage subscribing to this calendar), once the GH pages URL is certain.

[Mariatta]

Could we use something like hugo static site generator instead of a custom html generator? I just prefer to maintain the content and not the tooling.