user-manual: remove temporary branch entry from todo list
In the section on "How to check out a different version of a
project" the "new" branch is used as a temporary branch. A detached
HEAD was not used since it was a new feature introduced just a
couple weeks prior.
The section could be changed to use and explain a detached HEAD,
except that would increase the learning curve early in the manual.
Detached HEADs are discussed a couple sections later under
"Examining an old version without creating a new branch".
Let's declare that it is a bad idea to rewrite the example that
uses a temporary branch to do the sightseeing on a detached HEAD.
Signed-off-by: Stephen P. Smith <ischis2@cox.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>