docs: Update community page
docs: Update community page

There's been a few changes lately, for instance we are trying a shorter
format for the weekly meeting, and the eBPF library channels have shifted
around. While we're at it, fix up some formatting / grammar /
consistency for the page overall.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

cilium/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium