add make for docs (#5685)

* add make docs

* docs

.github/CONTRIBUTING.md

@@ -104,6 +104,12 @@ Most of the tests in PyTorch Lightning train a trial MNIST model under various t
 
 ## Guidelines
 
+### Developments scripts
+To build the documentation locally, simply execute the following commands from project root (only for Unix):
+- `make clean` cleans repo from temp/generated files
+- `make docs` builds documentation under _docs/build/html_
+- `make test` runs all project's tests
+
 ### Original code
 
 All added or edited code shall be the own original work of the particular contributor.

Makefile

@@ -1,19 +1,33 @@
-.PHONY: test clean
+.PHONY: test clean docs
+
+# to imitate SLURM set only single node
+export SLURM_LOCALID=0
+# assume you have installed need packages
+export SPHINX_MOCK_REQUIREMENTS=0
 
 test:
+	pip install -r requirements/devel.txt
 	# install APEX, see https://github.com/NVIDIA/apex#linux
-	# to imitate SLURM set only single node
-	export SLURM_LOCALID=0
 
 	# use this to run tests
 	rm -rf _ckpt_*
 	rm -rf ./lightning_logs
 	python -m coverage run --source pytorch_lightning -m pytest pytorch_lightning tests pl_examples -v --flake8
-	python -m coverage report -m
+	python -m coverage report
 
 	# specific file
-	# python -m coverage run --source pytorch_lightning -m py.test --flake8 --durations=0 -v -k
+	# python -m coverage run --source pytorch_lightning -m pytest --flake8 --durations=0 -v -k
+
+docs: clean
+	pip install --quiet -r requirements/docs.txt
+	python -m sphinx -b html -W docs/source docs/build
 
 clean:
 	# clean all temp runs
-	rm -rf $(shell find . -name "mlruns" )
+	rm -rf $(shell find . -name "mlruns")
+	rm -rf .mypy_cache
+	rm -rf .pytest_cache
+	rm -rf ./docs/build
+	rm -rf ./docs/source/generated
+	rm -rf ./docs/source/*/generated
+	rm -rf ./docs/source/api