Changed `async.map` to `async.mapLimit` in mapLimit example
Merge pull request #394 from lupomontero/master

Changed `async.map` to `async.mapLimit` in mapLimit example
Update README to include links to all API functions.

Some of these ones are hard to find at a quick glance. Putting them in the index makes them easier to spot and find.
Merge pull request #408 from RickEyre/readme-fix

Update README to include links to all API functions.
Make results visible in series.