Upgrade riot-web (1.5.6 -> 1.5.7)

Regression introduced in 53186ffa1c

NeDB is deprecated, so we should transition away from it in the future.
Still, most of the functionality should work on this new version.

Remove spurious 'mxisd' string from mautrix bridge templates comment

Notes when not using a ssh key for authentication

Fixed small typo, added an extra note on how to use the ansible docker image when not using a ssh key for authentication

Update configuring-playbook-bridge-mautrix-telegram.md

typographical error

Update synapse (1.7.2 -> 1.7.3)

Related to #330 (Github Issue).

Fixes #330 (Github Issue).

Expose self service bridging in matrix_appservice_discord

This allows for users to bridge already existing matrix rooms to discord

Added Traefik configuration example to own webserver docs

Implement MSC1957: Integration manager discovery

Render vhost directives in https server block

https://github.com/matrix-org/matrix-doc/pull/1957

Yay Riot iOS now supports integration manager discovery!

Allow Synapse manhole to be enabled

Can you double check that the way I have this set only exposes it locally? It is important that the manhole is not available to the outside world since it is quite powerful and the password is hard coded.

Add telegram relay bot feature to playbook

Switch riot-web image (bubuntux/riot-web -> vectorim/riot-web)

Switching to the official image (vectorim/riot-web) should ensure:
- there's less breakage, as it's maintained by the same team as riot-web
- there's fewer actors we need to trust
- we can upgrade riot-web faster, as newer versions should be released
on Docker hub at the same time riot-web releases are made