rename "simple" deployment to "generic"

The main thing this section is really useful for is explaining how to
configure various reverse proxies, which applies to basically anything.

Also, remove all the language about this being "recommended", because
nothing in this documentation is actually tested in CI.

Signed-off-by: strawberry <strawberry@puppygock.gay>

docs/SUMMARY.md

@@ -5,7 +5,7 @@
 
 - [Example configuration](configuration.md)
 - [Deployment options](deploying.md)
-    - [Simple (Recommended)](deploying/simple.md)
+    - [Generic](deploying/generic.md)
     - [Debian](deploying/debian.md)
     - [Docker](deploying/docker.md)
     - [Nix](deploying/nix.md)