Go on Docker Swarm

Updates the `Go on Docker Swarm` use case to europa config. Diagrams are also included for better UX

Signed-off-by: guillaume <guillaume.derouville@gmail.com>

docs/tests/use-cases/go-docker-swarm/build-action.cue.fragment

@@ -0,0 +1,20 @@
+build: {
+	luaDocs: docker.#Dockerfile & {
+		source: client.filesystem."./lua-docs".read.contents
+	}
+
+	_addGithubSHA: core.#WriteFile & {
+		input:    luaDocs.output.rootfs
+		path:     "/www/github_sha.yml"
+		contents: #"""
+					keywords: ["particubes", "game", "mobile", "scripting", "cube", "voxel", "world", "docs"]
+					title: "Github SHA"
+					blocks:
+					    - text: "\#(client.env.GITHUB_SHA)"
+					"""#
+	}
+	image: docker.#Image & {
+		rootfs: _addGithubSHA.output
+		config: luaDocs.output.config
+	}
+}