Use a consistent branching model

[oscar-g]

Thank you for the great theme. I am enjoying creating a documentation website with it!

I noticed that the Develop and Master branches don't really make sense right now (Network Graph).

Specifically, the Develop branch is missing a few commits from Master (one of those commits is actually duplicated in both branches, at different times, and different authors).

I propose adopting the popular branching model: Gitflow; I also think using verioning will help advance the project.

To do this, we should:

1. Merge Master into Develop
2. Merge contributions via pull request only to Develop
3. When ready, merge Develop into Master and bump the version number.

The reason why I made this issue is that I am not really sure what branch is more complete....they both seem to have small differences that should be included in both branches.

Take a look at my Develop fork with the current Master merged in.

Any thoughts?