docs: add make universe

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

Makefile

@@ -30,7 +30,7 @@ shellcheck:
 	shellcheck ./tests/*.bats ./tests/*.bash
 
 .PHONY: lint
-lint: shellcheck cuelint golint check-buildkit-version
+lint: shellcheck cuelint golint check-buildkit-version universelint
 
 .PHONY: check-buildkit-version
 check-buildkit-version:
@@ -50,6 +50,14 @@ integration: dagger-debug
 install: dagger
 	go install ./cmd/dagger
 
+.PHONY: universe
+universe: dagger
+	./cmd/dagger/dagger doc --output ./docs/reference/universe --format md
+
+.PHONY: universelint
+universelint: universe
+	@test -z "$$(git status -s . | grep -e "^ M"  | grep docs/reference/universe | cut -d ' ' -f3 | tee /dev/stderr)"
+
 .PHONY: docs
 docs:
 	yarn --cwd "./website" install

docs/reference/_category_.json

@@ -0,0 +1,4 @@
+{
+  "label": "Reference",
+  "position": 5
+}

docs/reference/universe/_category_.json

@@ -0,0 +1,3 @@
+{
+  "label": "Universe"
+}