Temporarily remove Use Cases from the Europa docs sidebar

The current plan is to add them post 0.2.0 shipping, for now the focus
is on Getting Started & Core Concepts.

Signed-off-by: Gerhard Lazu <gerhard@lazu.co.uk>

docs/use-cases/1211-go-docker-swarm.md

@@ -58,7 +58,7 @@ dagger.#Plan & {
         // - stop container
       }
 
-      push: docker.#Push {
+      push: docker.#Push & {
         dest: inputs.params.image.ref
         image: build.output
       }