Remove asterisks from configuring-dns.md

These previously denoted optional DNS records but now optional records are a separate table so they are unnecessary.

Update hydrogen main.yml

update to v0.2.0

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1140

Update prometheus  v2.27.1 -> v2.28.0

Coturn update 4.5.2 -> 4.5.2-r2

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1131

The new one is based on Alpine 3.14, instead of Alpine 3.13.

Add support for CentOS (Stream) 8

according to discussion in channel not needed anymore

Content-Security-Policy For Element Web

Update grafana 8.0.2 -> 8.0.3

https://github.com/vector-im/element-web#configuration-best-practices

Should have been part of 9daeb39710

Update configuring-playbook-synapse.md

Added an example for configuring the variables for the OpenID, that might fails because the variables are not defined for the playbook parsing, but Synapse's own config file parsing.

GoMatrixHosting v0.5.0

update hydrogen v0.1.56 -> v0.1.57

Update grafana 8.0.0 -> 8.0.2

https://github.com/vector-im/hydrogen-web/releases/tag/v0.1.57

Add ability to configure jitsi-prosody to load custom modules

coturn update

Update grafana 7.5.7 -> 8.0.0

Update element 1.7.29 -> 1.7.30

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1108

fix error when running with Ansible 2.7 in the hydrogen setup

Update IRC appservice

Without this the hydrogen task would fail for Ansible 2.7 even when hydrogen is not enabled.