Commit ckp_slim.xml

Once ckp_slim can be generated (@see #7 (closed)), the ckp_slim database should be made available to the general public, ... or less general public (ie. our notebooks, as long as the Estrades project).
This means:

• hosting it in this repo
• commits of new ckp_slim versions should be done either automagically (daily?)
• testing if shared repos are something we likes ; if, on the contrary, Estrades' PM wants the repo to be duplicated, we gotta decides if he does it himself or if we do it for him