git-reset.txt: reset --soft is not a no-op

Make it clearer that git reset --soft actually does something (changing
HEAD). While it is mentioned in the previous paragraph already it can
be easily overlooked otherwise.

Also, git reset --soft does not look at the index nor the worktree, so
there is no "good order" requirement.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-reset.txt

@@ -42,10 +42,10 @@ linkgit:git-add[1]).
 +
 --
 --soft::
-	Does not touch the index file nor the working tree at all, but
-	requires them to be in a good order. This leaves all your changed
-	files "Changes to be committed", as 'git status' would
-	put it.
+	Does not touch the index file nor the working tree at all (but
+	resets the head to <commit>, just like all modes do). This leaves
+	all your changed files "Changes to be committed", as 'git status'
+	would put it.
 
 --mixed::
 	Resets the index but not the working tree (i.e., the changed files