Comments about the doc

[AlexandreMary]

Hi,
I just had a look at the new doc, nice work, makes it much more easy to enter in Vortex I believe.

A few comments :

• vtx.task() : that may be confusing with the concept of Task in the mkjob layout; could it be renamed or rather aliased ? (I get that Algocomponent was not very explicit)
  Also, I did not find documnetation about the purpose of AlgoComponents, is it just not done yet ?
• a detail, but the Copyright mention says 2012-2015
• Data-tree: they are not much used in the data-tree, but non-flow (or static) resources don't have the date level
  Example of use: PGD or clim files generated within Vortex, Davai build expertise files...
  Worth to be mentioned ?
• Isn't test also a "special experiment" ?
• configuration files: I understand they can be anywhere and loaded using config.load_config(relative/path/to/config.toml), right ? Maybe this could be more explicit somewhere.