Fix typo, cleanup Makefile, add installation instruction

Author: shoumikchow

CONTRIBUTING.md

@@ -82,7 +82,7 @@ Ready to contribute? Here's how to set up `bbox_visualizer` for local developmen
     flake8 bbox_visualizer demo
     ```
 
-   To get flake8, just pip install int into your virtualenv.
+   To get flake8, just pip install it into your virtualenv.
 
 6. Commit your changes and push your branch to GitHub::
 

Makefile

@@ -54,6 +54,8 @@ docs: ## generate Sphinx HTML documentation, including API docs
 	rm -f docs/bbox_visualizer.rst
 	rm -f docs/modules.rst
 	sphinx-apidoc -o docs/ bbox_visualizer
+	rm -f docs/bbox_visualizer.rst
+	rm -f docs/modules.rst
 	$(MAKE) -C docs clean
 	$(MAKE) -C docs html
 	$(BROWSER) docs/_build/html/index.html

docs/installation.rst

@@ -46,6 +46,12 @@ Once you have a copy of the source, you can install it with:
 
     $ python setup.py install
 
+or 
+
+.. code-block:: console
+
+    $ pip install . --user
+
 
 .. _Github repo: https://github.com/shoumikchow/bbox-visualizer
 .. _tarball: https://github.com/shoumikchow/bbox-visualizer/tarball/master