moves Markdown wrapper down to where the post $intro is defined

the Markdown function wasn't doing anything in the home page section of the `/dropplets/index.php`, however, if you wrap the intro text with the Markdown function in the get_all_posts function lower down, the Markdown is interpretted correctly. Removed the Markdown wrapper from $content and added it to $fcontents[4] in get_all_posts()
removes redundant `<p>` tags

with the change to the get_all_posts() function to move the Markdown interpretation to where the $intro is defined, the home page adds a couple empty `<p></p>` tags, which results in the intro being indented via the basic css `p + p` rules. This removes the `<p>` tags from `/template/posts.php` since the `<p>` tags are being added by the Markdown anyway.
Merge pull request #12 from jazzsequence/master

Fixes markdown issues on home page.