Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/904

This reverts commit fd3d48bb6d.

Normally this environment variable gets referred to from `settings.json.docker`,
but we have our own full configuration, which hardcodes `"trustProxy": true`,
thus making this useless.

This has been pointed out here:
fd3d48bb6d (commitcomment-47403097)

Added paragraph about updating DNS to get stats

This document didn't describe that it is necessary to have a DNS-entry for stats sub-domain.

Recommend a better way of backing up postgres

don't spawn an extra container
run pg_dumpall within matrix-postgres instead, ensures correct version
store under /matrix so a backup of the folder will contain a DB dump
use absolute paths just in case something in the ENV is messed up

Update lower power config example

All other examples show the config to lower the memory usage on the server

added "matrix_%SERVICE%_version" variable to all roles

Update Telegram bridge setup link

Same reasoning as in 1cd251ed78

Change markdown to use link instead of tags for Telegram App setup

add support for mautrix-instagram

This only seems to be affecting some people badly enough to cause
matrix-postgres not to start. Certain systemd versions probably handle
it better or something.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/889
(hopefully)

This probably got lost somehow in all the work that happened in
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/456

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/887

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

Add mx-puppet-groupme support

Synapse workers

Adding more presets in the future would be nice.

We're talking about a webserver running on the same machine, which
imports the configuration files generated by the `matrix-nginx-proxy`
in the `/matrix/nginx-proxy/conf.d` directory.

Users who run an nginx webserver on some other machine will need to do
something different.

fix wrong json parameter in webhook documentation

Related to: https://matrix.org/blog/2021/02/18/synapse-1-27-0-released#dropping-armv7-docker-images

Add Netlify instructions

fixes HTTP 400 Error: "{\"errcode\":\"M_MISSING_PARAM\",\"error\":\"Missing key 'avatar_url'\"}"

Remove 'sqlite3' from the Etherpad role

The official Etherpad Docker image has no support for sqlite3 databases.

This give us the possibility to run multiple instances of
workers that that don't expose a port.

Right now, we don't support that, but in the future we could
run multiple `federation_sender` or `pusher` workers, without
them fighting over naming (previously, they'd all be named
something like `matrix-synapse-worker-pusher-0`, because
they'd all define `port` as `0`).

Use the yaml callback plugin when running ansible-playbook

The default default Ansible screen output encodes and prints error outputs as a hard to read dense line of JSON.
This patch changes the ansible-playbook command behavior for this project to output yaml instead.

Update synapse-admin (0.6.1 -> 0.7.0)

Change the new app link to use classsic apps

Until [this issue](https://github.com/matrix-org/matrix-appservice-slack/issues/348) is fixed

Related to:
- https://github.com/matrix-org/synapse/pull/9407
- https://github.com/matrix-org/synapse/pull/7855