introduce bingo and rework makefiles

docs/Makefile

@@ -1,5 +1,7 @@
 SHELL := bash
 
+include ../.bingo/Variables.mk
+
 .PHONY: help
 help:
 	@grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
@@ -25,12 +27,12 @@ docs-copy: ## copy docs to hugo
 	rsync -ax --delete --exclude hugo/ --exclude Makefile --exclude .gitignore --exclude README.md ../. content/; \
 
 .PHONY: docs-serve
-docs-serve: docs-generate docs-copy ## serve docs with hugo in docker
-	@docker run --rm --network host -v $(shell pwd)/hugo:/src owncloudci/hugo:0 server
+docs-serve: $(HUGO) docs-generate docs-copy ## serve docs with hugo
+	cd hugo && $(HUGO) server
 
 .PHONY: docs-serve-simple
-docs-serve-simple: config-docs-generate docs-copy ## serve docs with hugo installed on system
-	cd hugo && hugo server
+docs-serve-simple: $(HUGO) config-docs-generate docs-copy ## serve docs with hugo without protobuf generation
+	cd hugo && $(HUGO) server
 
 .PHONY: clean
 clean: ## clean up docs build artifacts