Update community page to list new Zoom meeting ids

[ivanvc]

The community page (https://etcd.io/community/) still lists the previous Zoom link. Some meetings also don't appear there. Also, the format is different per meeting.

Ideally, we should, in order of importance:

1. Update the Zoom links to match the current meeting IDs that we're using.
2. Add any meetings that are not listed there (i.e., docs meeting).
3. Update the format so it's easier to find the meetings in the list and so it doesn't look like it was written by many people.

/cc @jberkus