Remove Twitter and Facebook links from READMEs and footer

[christophdubach]

We don't really use these channels actively, so we could remove the links – what do you think?

Btw, we have currently more than 2000 followers on Twitter aka X, and more than 700 Facebook followers.

[backflip]

@christophdubach, I would very welcome removing both links as we do not curate these channels.

Second question would probably be: Do we keep the channels at all? I would very, very much prefer Mastodon and/or possibly Bluesky in case we want to use social media channels.

I think at least one channel where we monitor incoming communication. For everyone having ADG related input or questions. I would be fine with monitoring a Mastodon account, for example.

[backflip]

From our meeting:

• Let's remove both, but keep the X account for archiving purposes. The Facebook link was pointing to Access for All anyway.
• Let's use our own accounts for outgoing stuff.