Shorten h2network permalink
Move Raster below Applications
Replace Applications -> H2Network

It is the only application for now and NoiseM@p will have its own
website.

Note that on the mobile website, we keep the 'Applications' separator in
doc_contents_mobile.html.
Attract attention to H2Network
Revert "Replace Applications -> H2Network"

This reverts commit ae3a0101b16c91667139c3d7cffe8568bb1eef12.
Keep 'applications' in category attribute