Add a table of contents to the docs.

[rdlester]

Could we add a "table of contents" to the top of the readme / website? Just add ids to each section header (and maybe divide things up into more subsections, even), then add a bulletpoint list of sections to the top that links to the section ids.

Not the biggest issue in the world, but I've come back to the docs looking for a particular detail and have either had to scroll around a whole bunch or try to guess what terms might occur nearby but not anywhere else. It might also make the giant README a little less intimidating to newcomers.

[Valloric]

This would be a nice thing to have, agreed.