evolve: improve the help of the fold command The help of the fold command needed a little rework. This patch makes it a little less verbose and adds an example. It also highlights a little more the importance of the --exact flag.

syntax: re
/figures/[^/]+\.png$
^docs/build/
^docs/html/
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
\.err$
^tests/easy_run.sh$
^build/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$