Add iCal Support

[BBloggsbott]

I feel it will be nice to be able to push public iCal calendars to this website.

[rjzupkoii]

Looking at this a second time, it doesn't appear that this would be possible since GitHub requires the backend be contained within the repository. So we we can render things that read read static content, and basic blogging is possible by saving to the repository, but any sort of dynamic storage is not possible.