enhance code clarity

enhance code clarity

+ doc evaluation
+ doc renouvellement
+ style bouton

lien "réseau" vers la section de la présentation du groupe #111

Also for the mesocenters list.

Found by validator.w3.org

To fix some accessibility issues

By adding a space in its content ... (it is used to format the twitter
caroussel buttons)

Since it not an unique identifier (e.g. in the archives, for each year)

Since it is not an unique identifier (e.g. the cards)

Since it is not an unique identifier.

- on parcourt les articles dans l'ordre décroissant des dates (liste `articles`)
- on ajoute l'article à la sélection s'il en existe au plus un de la même catégorie dans la liste des sélectionnés
- on s'arrête à 5 (le nombre affiché sur la page d'accueil)

Due to empty articles list or containing no valid categories when
generating archives, paginated index or something else...

This block is loaded **after** the external scripts so that other
templates can add scripts that depend on external scripts.

We should also load the external scripts at the body beginning but it is
not a good idea since they will be launched on a possibly partialy
loaded html code.

- fixing links size (the clic zone was huge)
- hashtag are now clickable
- adding refresh icon (but refresh is not implemented)
- fixing vertical bar in tweet header
- adding comma on top of the frame

This reverts commit 09022396.