Adding support for OVHcloud and tlschallenge

[bsamadi]

I added docker-compose.yml files for OVHcloud and tlschallenge certificate resolvers. I just wanted to share them with you. Thank you for your work. That is exactly what I was looking for.

[bsherman]

My apologies, I somehow managed to overlook this PR for an embarrassingly long time.

I see the new files you've added are swapping out the Traefik certificate resolver configuration. I appreciate it and this is useful information for anyone wishing to use Traefik in a different configuration, but I'm concerned about adding code which looks "ready to run" but which I won't be testing.

What do you think about contributing a new markdown file which talks about how to make these changes? It could include your changes, plus link to the Traefik docs maybe?