refactor: Rename all remaining conduwuit references to Continuwuity

Also adds an alias for the old binary name to the dockerfile

Supersedes !1485
Closes #1536
Closes #2277

docs/deploying/docker.mdx

@@ -247,7 +247,7 @@ Get a working Continuwuity server with an admin user in four steps:
       -e CONTINUWUITY_ALLOW_FEDERATION="false" \
       --name continuwuity \
       forgejo.ellis.link/continuwuation/continuwuity:latest \
-      /sbin/conduwuit
+      /sbin/continuwuity
     ```
 
 3. Fetch the one-time initial registration token