* _config.yml: disable twitter_username
* _includes/head.html: comment showing deactivated Twitter account as
the author.
* pages/some.markdown:
* simply tell people to check the keys page (this should be a
link, #122).
* Remove Facebook Messenger (still exists, but doesn't belong here,
GitHub organisation notice, Facebook notice from Goodreads,
Twitter link and DigitalOcean reflink (I am thinking of removing
that account when the current credits expire).
* r/1024.html: use https
* r/fb-aseksuaalit.md & r/heseta-naiset.md: it's difficult for me to
know if there are changes to these links as I am not in Facebook and
the assosiation is question has renamed themselves.
* r/twitter.md: link to the Mastodon toot on account removal instead.
* I cannot think of a better place for it to link if I won't simply
remove it now.
