[FAB-10133] Update docs to reflect new fetch log lvl

"peer channel fetch" nows logs its success message at the
info level instead of debug. This CR updates the documentation
accordingly (and also pulls in a few other recent CLI changes
that resulted from running `make help-docs`).

Change-Id: I1c95d41176078d89d1f555d078aa8739e50707e3
Signed-off-by: Will Lahti <wtlahti@us.ibm.com>