This commit adds entries for the 'gen-bounds' and 'outdated'
commands to the "cabal-install Commands" section of the user manual.

Formerly, those commands were only described in the "Package
description" section. Some, but not all, of the information in that
section has been moved to the entires in the list of commands.

This commit changes two other things:

- The descriptions in the "Package description" were incorrectly placed
  as sub-sections of "Opening an interpreter session". They have been
  moved one level up.

- changed the gen-bounds example, because it used dependencies which
  *already* had bounds as the starting point.

Co-authored-by: Daniel Díaz <diaz_carrete@yahoo.com>
Co-authored-by: Emily Pillmore <emilypi@cohomolo.gy>
Co-authored-by: gbaz <gershomb@gmail.com>