Help Tab

Once again my most sincere apologies for all the spam.

Since I can't seem to figure out how to keep feature branches from eating themselves on merge, this pull request has all the changes I've made in my fork of bootstrap-shortcodes including organizing the files into an includes subdirectory, and the Help Tab.

Both you, @simonyeldon, and @filipstefansson should weigh in on whether we want the help tab or not. It's a pretty significant design decision and it's not one I, as a contributor who opens and closes ten incorrect pull requests in a day, am comfortable making. Details are below:

**Help Tab**
This is a tab that will appear next to the "Add Media" button in WordPress. It pops up a ThickBox showing the README.md documentation, which means there's only one piece of documentation to update.

I think that our target audience with these shortcodes is slightly more advanced than your average end-user. As such I think showing the documentation is a really good way to educate and inform without cluttering up TinyMCE with tons of buttons.

What Bootstrap user isn't constantly referring to documentation?

Here's what the tab looks like:
![screen shot 2013-09-14 at 7 55 03 am](https://f.cloud.github.com/assets/2457670/1154575/0f845f90-1f4b-11e3-97e5-178e99d3e668.png)

And here's the popup it displays:
![screen shot 2013-09-16 at 10 20 33 am](https://f.cloud.github.com/assets/2457670/1154578/16b44e42-1f4b-11e3-9ad5-d9deb2d31204.png)