first working figure liquid tag plugin
figure.rb: fixed regex; breaks softer; figcaption markdownified
changed file name for figure_tag plugin, added brief documentation
updates to posts with new figure structured, underscores for front matter
catching the plugin up to the latest (better notes, slight refactor)
Merge pull request #58 from opattison/alt-tags-for-images-in-posts

Alt tags for images in posts, new figure plugin - solves #46