Added clarification for RSS doc page.
* a little formatting to make key words jump out
* emphasize that you can create your own
* add how to link to the feed in <head>
* add what .RSSlink does
* added point that a link to an RSS feed should be of type application/rss+xml
Among the various changes, most instances of
{{ template "partials/FILE.html" . }}
were changed to
{{ partial "FILE.html" . }}
Also, in main.go, change "2013" to "2013-14".
