Relative paths and removed href's from links
Added MathJax to the draft
Added information on GitHub to the code view

The text behind the 'updates' link would explain that the website is
not a realtime version of the Git project, and could discuss the "Added
new tags" commit messages as indicators of when things have been
updated. If this is a good idea, of course, but I think a tighter
integration would be beneficial.
Added a 'meta' section to the sidebar

Not sure whether this is essential, but the displaying trick I tried is
useful in a later stage. There could be more interesting meta
information too.
Added comments from tag 02RB

The default style seems okay, but of course this is not really
browser-independent, so some tweaking might be required.

And for some reason I try to use single quotes in HTML, double quotes in
JS. Maybe I have OCD.
Fixed title behaviour for show / hide comments
The label of the tag is interesting meta info

It is displayed in the current version of the website, so for now I'll
do the same in the new layout.
Complete area of link in menu clickable

And I slightly changed the spacing to something I find more agreeable.
Copied comments section

Minor displaying updates, started using a <noscript> tag concerning the
preview (I should only write the explanation of the preview option when
JS is enabled). A preliminary form validation in JS would be nice too.
Moved CSS to separate folder, and split files
Forgot to add css/main.css
Fixed bug in code / rendered toggle

By moving the thing to an inline function I didn't add the event
parameter.