Bug fixes

- Show the correct post date on the index
  - it was defaulting to today because it was looking for the date for
    /src/posts/blah.html instead of src/posts/blah.html
- Remove extra 'alt' attributes from links
  - These should've been removed in
9c99f0f64f71823c2de01e48bb33562aba7c23cd, but I forgot to rebuild
index.html
Make it clear where the content is

- Remove the menu from the post's content
- Mark main post content up with article tags instead of section tags
  - This should enable the 'reader' button on safari for OS X and iOS
    - Thanks: http://mathiasbynens.be/notes/safari-reader
- Where possible keep markup out of the makefile