Element web : update welcome page template

Add support for postgres 13

I don't believe Ansible v1 would even go as far as executing this
sanity check, but.. Adding an extra defensive check for completeness.

Client well known compatibility

Related to #658 (Github Issue).

Related to #658 (Github Issue).

According to the docs, "e2ee" is already under "io.element":
  https://github.com/vector-im/element-web/blob/develop/docs/e2ee.md#disabling-encryption-by-default
however "jitsi" is still under "im.vector.riot":
  https://github.com/vector-im/element-web/blob/develop/docs/jitsi.md#configuring-element-to-use-your-self-hosted-jitsi-server

For now let's just maintain backward and forward compatibility for both
settings since the client version is out of the control of this
playbook.

Allow configuration of Element's bug_report_endpoint_url and showLabsSettings

showLabsSettings is the new enableLabs I guess. enableLabs doesn't seem to do anything anymore. It had been deprecated for a while.

This PR also removes @riot-bot:matrix.org as the default welcome_user_id since it doesn't exist anymore.

New docker image appservice-slack

Fixed dead link to mx-puppet-discord

Update configuring-playbook-dimension.md

Improved formatting for a header that was attached to the previous paragraph (...by inserting a newline).

Corrects the Caddyfile

Update element (1.7.5 -> 1.7.7)

Use the same naming convention as the other mx-puppet suite.

Caddy2 Caddyfile example and Comment in examples/host_vars.yml

Update configuring-playbook-jitsi.md

Changes matrix_dimension_integrations_ui_url from /riot to /element h…

PullRequest

Removes DS-Store

Fix links to using your own webserver doc