Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1621

This announces matrix-hookshot support that got added in
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1505

This is an attempt to address this:
dc893485d1 (commitcomment-63097721)

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/818

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1511

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1509

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1478

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1459
and https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1452

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1401

https://github.com/mautrix/facebook/releases/tag/v0.3.2 says that this
version re-adds SQLite support.

Related to c4d2c8394c

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1323
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1328
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1329

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1242

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1055

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/999

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/962

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/683

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/872

propose explicit showing single quotes around the password, since I forgot to put them there.

I got at least a few reports of people pasting these statements one by
one and missing the `;`.

In short, this makes Synapse a 2nd class citizen,
preparing for a future where it's just one-of-many homeserver software
options.

We also no longer have a default Postgres superuser password,
which improves security.

The changelog explains more as to why this was done
and how to proceed from here.

I had intentionally held it back in 39ea3496a4
until:
- it received more testing (there were a few bugs during the
migration, but now it seems OK)
- this migration guide was written

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/756

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/737

I feel like timers are somewhat more complicated and dirty (compared to
cronjobs), but they come with these benefits:

- log output goes to journald
- on newer systemd distros, you can see when the timer fired, when it
will fire, etc.
- we don't need to rely on cron (reducing our dependencies to just
systemd + Docker)

Cronjobs work well, but it's one more dependency that needs to be
installed. We were even asking people to install it manually
(in `docs/prerequisites.md`), which could have gone unnoticed.

Once in a while someone says "my SSL certificates didn't renew"
and it's likely because they forgot to install a cron daemon.

Switching to systemd timers means that installation is simpler
and more unified.