Add key-chord for ido-dired.
Use Dired-X.

This calls use-package on Dired-X, and removes the C-x C-j binding,
which Dired-X binds. Also, this commit makes a "Dired" specific section,
including the previous dired-details section.
Specify local copy of HyperSpec for SLIME.

Can be accessed from SLIME with C-c C-d h.