git-sh-setup: document git_editor() and get_author_ident_from_commit()

These 2 functions were missing from the manpage.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-sh-setup.txt

@@ -44,6 +44,11 @@ set_reflog_action::
 	end-user action in the reflog, when the script updates a
 	ref.
 
+git_editor::
+	runs an editor of user's choice (GIT_EDITOR, core.editor, VISUAL or
+	EDITOR) on a given file, but error out if no editor is specified
+	and the terminal is dumb.
+
 is_bare_repository::
 	outputs `true` or `false` to the standard output stream
 	to indicate if the repository is a bare repository
@@ -57,6 +62,10 @@ require_work_tree::
 	if so.  Used by scripts that require working tree
 	(e.g. `checkout`).
 
+get_author_ident_from_commit::
+	outputs code for use with eval to set the GIT_AUTHOR_NAME,
+	GIT_AUTHOR_EMAIL and GIT_AUTHOR_DATE variables for a given commit.
+
 
 Author
 ------