Add makefile targets for building documentation.

Makefile

@@ -237,6 +237,17 @@ install-docker-extension : build-docker-extension
 update-docker-extension : build-docker-extension
 	$(MAKE) -C docker-extension update-extension REPOSITORY=$(IMAGE_REPOSITORY) TAG=$(PACKAGE_VERSION)
 
+project-docs/venv :
+	python3 -m venv project-docs/venv
+	project-docs/venv/bin/pip install -r project-docs/requirements.txt
+
+build-project-docs : project-docs/venv
+	source project-docs/venv/bin/activate && make -C project-docs html
+
+open-project-docs :
+	open project-docs/_build/html/index.html || \
+        xdg-open project-docs/_build/html/index.html
+
 deploy-workshop:
 	kubectl apply -f https://github.com/vmware-tanzu-labs/lab-k8s-fundamentals/releases/download/5.0/workshop.yaml
 	kubectl apply -f https://github.com/vmware-tanzu-labs/lab-k8s-fundamentals/releases/download/5.0/trainingportal.yaml
@@ -264,6 +275,7 @@ prune-builds:
 	rm -rf training-portal/venv
 	rm -rf client-programs/bin
 	rm -rf client-programs/pkg/renderer/files
+	rm -rf project-docs/_build
 
 prune-registry:
 	docker exec educates-registry registry garbage-collect /etc/docker/registry/config.yml --delete-untagged=true