No markup in shortdesc

The example parser and index template don't handle markup in the shortdesc element.  Use the docs element instead.
Strip tags from shortdesc (et al.) when parsing

This strips markup from elements with id attributes that we care about: title, shortdesc, tags.  This will only work for people who use `npm install && npm start` to browse examples.  The other example parser doesn't strip this markup, so it should still not be used in these elements.
Merge pull request #1952 from tschaub/shortdesc

No markup in shortdesc.