disable install scripts and fix duplicate targets

.make/docs.mk

@@ -1,7 +1,12 @@
+
+SKIP_CONFIG_DOCS_GENERATE ?= 0
+CONFIG_DOCS_BASE_PATH ?= ../docs/extensions
+
 .PHONY: config-docs-generate
 config-docs-generate: $(FLAEX)
-	@echo "$(NAME): generating config docs"
-	@$(FLAEX) >| ../docs/extensions/$(NAME)/configuration.md
+	@if [ $(SKIP_CONFIG_DOCS_GENERATE) -eq 1 ]; then \
+		$(FLAEX) >| $(CONFIG_DOCS_BASE_PATH)/$(NAME)/configuration.md \
+	; fi;
 
 .PHONY: grpc-docs-generate
 grpc-docs-generate: buf-generate