Add NodeJS package script to watch and serve changes on Docs CSS (#47)

* Add NodeJS package script to watch and serve changes on Docs CSS

This is to allow working on the Docs CSS source without having to run make build-docs every time you make a change, and to serve the docs locally with live-reloading CSS, for easy local development.

* Create makefile target for docs devserver

.gitignore

@@ -147,4 +147,5 @@ kedro.db
 kedro/html
 docs/tmp-build-artifacts
 docs/build
+docs/node_modules
 docs/source/04_user_guide/source/.ipynb

Makefile

@@ -1,4 +1,4 @@
-install: docs/build/html/index.html
+install: build-docs
 	cp -r docs/build/html kedro
 	pip install .
 
@@ -7,8 +7,6 @@ clean:
 	find . -regex ".*/__pycache__" -exec rm -rf {} +
 	find . -regex ".*\.egg-info" -exec rm -rf {} +
 
-docs/build/html/index.html: build-docs
-
 install-pip-setuptools:
 	python -m pip install -U "pip>=18.0, <19.0" "setuptools>=38.0, <39.0" wheel
 
@@ -33,5 +31,8 @@ SPHINXPROJ = Kedro
 build-docs:
 	./docs/build-docs.sh
 
+devserver: build-docs
+	cd docs && npm install && npm start
+
 package: clean install
 	python setup.py sdist bdist_wheel