Moved leaving_breadcrumbs to unpublished_articles

leaving_breadcrumbs is not coming together very well.
It needs to be in the unpublished folder until it
gets better.
Added introductions to two blogs

The blog considers introductions to be the text before the
first # symbol in the markdown file.  So I added some
atx-style headers to my document.
Bugfix Intro now displays in index.html

Wheat considers the introduction of an article to be anything
before the first ##header in the markdown file.  For an
introduction to be displayed, there needs to be at least one
of the double-hashtag headers.