docs: add Commet client guide

[TheDataLeek]

Addresses #5001

• Add docs/configuring-playbook-client-commet.md with configuration, build-version note, install, and troubleshooting
• Link Commet docs from README.md and docs/configuring-playbook.md

Love the work @D4GU, thanks for the code changes, please let me know if anything in here is inaccurate/misleading/needs tweaking!

[luixxiul]

Blocks on commetchat/commet#789, I suppose. The playbook does not make the component available yet.

[TheDataLeek]

Yes, I believe the following config would work but I ran out of memory on my digital ocean droplet just now when attempting to deploy,

matrix_client_commet_enabled: true
matrix_client_commet_default_homeserver: "{{ matrix_domain }}"
matrix_client_commet_container_image_self_build: true
matrix_client_commet_container_image_self_build_repo: "https://github.com/D4GU/selfbuild-commet"
matrix_client_commet_version: "main"

Obviously this is not ideal and we should wait until that commet PR merges

[D4GU]

Yeah it blocks there. Thanks for checking it out. I'll check the docs later.
Its already built and in the container registry on my forked repo I just rebuilt it with the latest changes, takes a lot of resources because of flutter and rust otherwise, but didn't test it yet since the merge into the ansible main branch and the new commet release. You can also just fork the repo add the workflow and then switch it out with your own registry. I'm not affiliated with the developer, just used it for my own setup. :)

I set it up like this time.
matrix_client_commet_enabled: true
matrix_client_commet_container_image_self_build: false
matrix_client_commet_container_image: "ghcr.io/d4gu/selfbuild-commet:main"
matrix_client_commet_hostname: "commet.mydomain"
matrix_client_commet_default_homeserver: "matrix.mydomain"