docs(docker,delegation): Fix .well-known docs - check below for details

.well-known env var in example composes now point to `example.com:443`,
and are turned on by default for Caddy labels and the Traefik configs.
For the Caddyfile example, they're left uncommented. Added small
bulletpoint on how to use this env var. Consistencize all the
.well-known comments inside these composes.

I don't want to overly fix the example composes and get it wrong, so
this small change should be enough. Split-domain deployments are fully
outsourced to the Delegation page now, and some changes are also made
there to be more comprehensive.

docs/public/deploying/docker-compose.for-traefik.yml

@@ -27,13 +27,11 @@ services:
       CONTINUWUITY_PORT: 8008 # This must match with traefik's loadbalancer label
       #CONTINUWUITY_CONFIG: '/etc/continuwuity.toml' # Uncomment if you mapped config toml above
 
-      # We need some way to serve the client and server .well-known json. The simplest way is via the CONTINUWUITY_WELL_KNOWN
-      # variable / config option, there are multiple ways to do this, e.g. in the continuwuity.toml file, and in a separate
-      # see the override file for more information about delegation
+      # Serve .well-known files to tell others to reach Continuwuity on port :443
       CONTINUWUITY_WELL_KNOWN: |
         {
-        client=https://matrix.example.com,
-        server=matrix.example.com:443
+        client=https://example.com,
+        server=example.com:443
         }
 
 volumes: