Set up better redirections

[benoitvidis]

The last version of the document gets rid of index pages, which now redirect to the first content page.
Such redirections are handled via meta tags, which are slow and visible to the end-user.

Github has some documentation about how to set redirections with jekyll. There must be a way to handle them on gh-pages.
At the very worse, we can update all links to point to their real location.

[ballinette]

Imho, we don't have to redirect to the first content page (which is an arbitrary choice and is not always pertinent).
We should have a 'TOC' index page for each section of the documentation (with an optional description), and avoid any kind of redirections.

[scottinet]

@benoitvidis > is this problem still here?