Major changes

Added headers to archive and tag list pages with page number / tag on the right
Added basic markdown code for code blocks and Images
Added markdown to the about page, including tags for now (though the tag lists will never show the about page, you may way to link from it)
Changed markdown code for tags to :$$
Updated "first-post" to reflect markdown changes
Tweaked code formatting for mathmatical veriables (uneeded whitespace mainly)