Sort list.

not sure it deserves its own section, but I didn't really see it fitting in as "Social Media"

 The channel has been around for a few months and has around 20 users (mostly popping up when then need help :-)), and I believe the lower barrier of entry compared to IRC could help adoption.

As suggested by slink, added the `Upgrade` and `HTTP2-Settings` as
additional allowed common tokens in an incoming `Connection`-header for
the VCL workaround.