added initial documentation, and settings to fix issue #30

Added initial documentation, and settings to fix issue #30

@dyve

added the basic docstring for all template tags, but lack complete with documentation on what the function does, what the syntax (usage) and an advanced example. (I marked the locations may be necessary to fix with a "FIXTHIS")

this pullrequest, beyond documentation, also includes the following files:

HISTORY.rst - Contains the changelog
AUTHORS.rst - Contains all contributors from historic of commits
CONTRIBUTING.rst - Contains a contribuition guidelines

Sorry. Maybe there is some spelling errors. My original language is Brazilian Portuguese. I'm not a fluent speaker of the English language

to test my branch:

pip install -e git://github.com/luzfcb/django-bootstrap3.git@add-docs#egg=django-bootstrap3

Just as you're setting up automated tests to Travis using .travis.yml, you can set up a post-receive hook so that every time you commit a change to the docs, the Sphinx docs on readthedocs.org will be updated. https://read-the-docs.readthedocs.org/en/latest/webhooks.html