reset: update documentation to require only tree-ish with paths

When resetting with paths, we no longer require a commit argument, but
only a tree-ish. Update the documentation and synopsis accordingly.

Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-reset.txt

@@ -8,20 +8,20 @@ git-reset - Reset current HEAD to the specified state
 SYNOPSIS
 --------
 [verse]
-'git reset' [-q] [<commit>] [--] <paths>...
-'git reset' (--patch | -p) [<commit>] [--] [<paths>...]
+'git reset' [-q] [<tree-ish>] [--] <paths>...
+'git reset' (--patch | -p) [<tree-sh>] [--] [<paths>...]
 'git reset' [--soft | --mixed | --hard | --merge | --keep] [-q] [<commit>]
 
 DESCRIPTION
 -----------
-In the first and second form, copy entries from <commit> to the index.
+In the first and second form, copy entries from <tree-ish> to the index.
 In the third form, set the current branch head (HEAD) to <commit>, optionally
-modifying index and working tree to match.  The <commit> defaults to HEAD
-in all forms.
+modifying index and working tree to match.  The <tree-ish>/<commit> defaults
+to HEAD in all forms.
 
-'git reset' [-q] [<commit>] [--] <paths>...::
+'git reset' [-q] [<tree-ish>] [--] <paths>...::
 	This form resets the index entries for all <paths> to their
-	state at <commit>.  (It does not affect the working tree, nor
+	state at <tree-ish>.  (It does not affect the working tree, nor
 	the current branch.)
 +
 This means that `git reset <paths>` is the opposite of `git add
@@ -34,9 +34,9 @@ Alternatively, using linkgit:git-checkout[1] and specifying a commit, you
 can copy the contents of a path out of a commit to the index and to the
 working tree in one go.
 
-'git reset' (--patch | -p) [<commit>] [--] [<paths>...]::
+'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]::
 	Interactively select hunks in the difference between the index
-	and <commit> (defaults to HEAD).  The chosen hunks are applied
+	and <tree-ish> (defaults to HEAD).  The chosen hunks are applied
 	in reverse to the index.
 +
 This means that `git reset -p` is the opposite of `git add -p`, i.e.

builtin/reset.c

@@ -23,8 +23,8 @@
 
 static const char * const git_reset_usage[] = {
 	N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
-	N_("git reset [-q] <commit> [--] <paths>..."),
-	N_("git reset --patch [<commit>] [--] [<paths>...]"),
+	N_("git reset [-q] <tree-ish> [--] <paths>..."),
+	N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
 	NULL
 };