Added option for sub-sections

Along with sub-sections, each section is now wrapped in a <section> tag
Added option for sub-sections

Content Changes: Each section is now wrapped in a <section> and all sub-sections wrapped in a <div>. This makes sorting easier and should fix some of the highlighting issues

Nav Changes: The sub-sections are setup in a child <ol> to the the parent section's <li>
Cleaned the code up

Much needed re-organization of everything before I get too far into v2
Section condition fix

Need to test against the headings since we've added the "top" section to the section var
Merge pull request #13 from jimmynotjim/feature/add-sub-sections

Added support for sub-sections