Added support for the Go-NEB bot

This may be especially helpful to existing playbook users
who happen to find themselves installing Go-NEB later on.

Updated Element 1.7.22 -> 1.7.23

matrix-nginx-proxy: specify Origin header, comply with CORS

Self-checks against the .well-known URIs look for the HTTP header
"Access-Control-Allow-Origin" indicating that the remode endpoint
supports CORS. But the remote server is not required to include
said header in the response if the HTTP request does not include
the "Origin" header. This is in accordance with the specification
[1] stating: 'A CORS request is an HTTP request that includes an
"Origin" header.'

This is in fact true for Gitlab pages hosting and that's why the
issue was identified.

Let's specify "Origin" header in the respective uri tasks performing
the HTTP request and ensure a CORS request.

[1] https://fetch.spec.whatwg.org/#http-requests

Adding vars to synapse for private servers

We have a flow like this:
1. matrix.DOMAIN vhost (matrix-domain.conf)
2. matrix-synapse vhost (matrix-synapse.conf); or matrix-corporal container, if enabled
3. (optional) matrix-synapse vhost (matrix-synapse.conf), if matrix-corporal enabled
4. matrix-synapse container

We are setting `X-Forwarded-For` correctly in step #1, but were
overwriting it in step #2 with something inaccurate.

Not doing anything in step #2 is better than doing the wrong thing.
It's probably best if we append another reverse-proxy address there
though, although what we're doing now (with this patch) seems to yield
the correct result (when matrix-corporal is not enabled).

When matrix-corporal is enabled, we still seem to do the wrong thing for
some reason. It's something to be fixed later on.

Make steps in configuring-playbook.md numbered

instead of bullet points which make it more difficult to tell whether or not you completed all of the steps

Adjust wait timeout

During first setup postgres takes its time to get up and running, resulting in "postgres in startup" exceptions from synapse if you run without additional services that come in between. Hence suggesting increasing the time a bit to avoid having an error which heals itself and thus is hard to spot for newcomers.

Added nginx proxy worker configuration to template and defaults

This is something that got lost during
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/456
and more specifically 4d62a75f6f.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/914

Mostly affects people who disable the integrated `matrix-nginx-proxy`.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/456
and more specifically 4d62a75f6f.

They're gone now: b8ce80e476

Run Let's Encrypt renewal checks daily instead of weekly.

This ensures more timely updates of certifcates.

This seems to have been added to the list of "deprecated files to
remove" by mistake.

People who were disabling matrix-nginx-proxy (in favor of their own
nginx webserver) and also overriding `matrix_federation_public_port`,
found that the generated nginx configuration still hardcoded `8448`,
which forced their nginx server to use that, regardless of the fact
that `matrix_federation_public_port` was pointing elsewhere.

We now allow for the in-container federation port to be configurable,
and also automatically wire things properly.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/456

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