Related to 69f71f48

Stating "many times" makes me think there is a finite amount of times I can run it before it *will* start causing trouble. But this is not true. So just state it can me ran more than once without causing trouble :)

Fixes #562 (Github Issue)

Fixes #586 (Github Issue)

Related to #583 (Github Issue).

Related to #557 (Github Pull Request).

Related to #540 (Github Pull Request).

https://github.com/matrix-discord/mx-puppet-discord/issues/80

Thanks Sorunome for setting up the automated build

Related to #551 and #555 (Github Pull Requests).

Signed-off-by: Tulir Asokan <tulir@maunium.net>

added docs, added seperate service for database, pr comments

Related to #454 (Github Pull Request).

Related to #425 (Github Pull Request).

This fixes an incorrect indentation in the database specification for
appservice-irc which caused matrix-appservice-irc to refuse to start
with the remarkably unhelpful error message:

```
ERROR:CLI Failed to run bridge.
```

This also updates doc links to the new matrixdotorg repo because the
tedomum repo contains out-of-date documentation.

Related to #339 (Github Pull Request).

Bridge is setup to work on the matrix side with this, but the discord invite link is not automatically generated.

This makes all containers (except mautrix-telegram and
mautrix-whatsapp), start as a non-root user.

We do this, because we don't trust some of the images.
In any case, we'd rather not trust ALL images and avoid giving
`root` access at all. We can't be sure they would drop privileges
or what they might do before they do it.

Because Postfix doesn't support running as non-root,
it had to be replaced by an Exim mail server.

The matrix-nginx-proxy nginx container image is patched up
(by replacing its main configuration) so that it can work as non-root.
It seems like there's no other good image that we can use and that is up-to-date
(https://hub.docker.com/r/nginxinc/nginx-unprivileged is outdated).

Likewise for riot-web (https://hub.docker.com/r/bubuntux/riot-web/),
we patch it up ourselves when starting (replacing the main nginx
configuration).
Ideally, it would be fixed upstream so we can simplify.