Alter "preview" task within the Makefile to add local path to the HTML version of the documentation for easier pick-up / preview

Author: mattkomarnicki

Makefile

@@ -12,7 +12,8 @@ build: src node_modules
 	docker run -it --init --rm -v $(PWD):/code -w /code node:9 npm run build
 
 preview: build
-	docker run -it --init --rm -v $(PWD):/code -w /code apiaryio/client preview --path=/code/apiary.apib --output=/code/apiary.html
+	docker run -it --init --rm -v $(PWD):/code -w /code apiaryio/client preview --path=/code/apiary.apib --output=/code/apiary.html && \
+    echo "\nView documentation at file://$(PWD)/apiary.html"
 
 watch: node_modules
 	docker run -it --init --rm -v $(PWD):/code -w /code node:9 npm run watch