Use helm-docs to automatically generate Helm docs

Problem: It's hard to keep the README up-to-date and it's a manual process

Solution: Use norwoodj/helm-docs to automatically generate the docs from the values.yaml file

.github/workflows/ci.yml

@@ -75,6 +75,10 @@ jobs:
       - name: Check if generated manifests are up to date
         run: make generate-manifests && git diff --exit-code
 
+      - name: Check if helm docs are up to date
+        run: make helm-docs && git diff --exit-code
+
+
   unit-tests:
     name: Unit Tests
     runs-on: ubuntu-22.04

Makefile

@@ -191,6 +191,10 @@ njs-unit-test: ## Run unit tests for the njs httpmatches module
 lint-helm: ## Run the helm chart linter
 	docker run --pull always --rm -v $(CURDIR):/nginx-gateway-fabric -w /nginx-gateway-fabric quay.io/helmpack/chart-testing:latest ct lint --config .ct.yaml
 
+.PHONY: helm-docs
+helm-docs: ## Generate the Helm chart documentation
+	docker run --pull always --rm -v $(CURDIR):/nginx-gateway-fabric -w /nginx-gateway-fabric jnorwood/helm-docs:latest --chart-search-root=charts
+
 .PHONY: load-images
 load-images: ## Load NGF and NGINX images on configured kind cluster.
 	kind load docker-image $(PREFIX):$(TAG) $(NGINX_PREFIX):$(TAG)

charts/nginx-gateway-fabric/.helmignore

@@ -1,2 +1,3 @@
 # Patterns to ignore when building packages.
 *.png
+*.gotmpl