Use ikiwiki's automatic referencing of HTML ids in table of content

See 02db6116.

For example:

• [[!toc]]
  <h1 id="my-section">My section</h1>
  

  Creates a hyperlink to #my-section in the table of content instead of a hyperlink to #index1h1 that might change with the structure of the page.

We should use this trick on our pages that have long tables of content that are often used to references specific sections.

It's at least worth applying this to:

$ git grep -c 'a id=' -- "*.*m*" | egrep -v '^(contribute|blueprint|news)' | sed 's/:/ /' | sort -hrk 2 | less

• support/faq 46
• support/known_issues.mdwn 21
• support/known_issues/graphics.mdwn 16
• doc/first_steps/introduction_to_gnome_and_the_tails_desktop.mdwn 16
• about/contact.mdwn 15
• doc/anonymous_internet/Tor_Browser.mdwn 11