* Fix headers and header anchor tags
The markdown parser already generates unique ids for header elements by
downcasing all of the words and replacing spaces with hyphens. Knowing
this, we can take the code blocks out of the headers and use the
generated ids as the link targets.
Aside: I tried to see if there was a standard way of documenting
subresources, but couldn't really find one. Both the aws_elb and
aws_instance resources seem to just say "documented below" without a
link. Then the relevant section is just a new paragraph with a list of
arguments.
* Reformat long lines
I find 80 character lines and whitespaces make the lists much easier to
read :)
* Remove extraneous <a> tags for header anchor tags
Now that middleman generates anchor tags for headers automagically, we
don't need to have blank <a> tags for anchor links to use.
