Permutations in LMFDB

This is my permutations directory.

It is really simple and may be used to create new directories (pages).

I won't probably work on it again in the next future. So you might prefer not to merge it.

For instance, I am not sure the url for a permutation is what we want... Hence, this might change in the future should maybe be fixed before merging it...

Cheers,

Sébastien