doc: group pretty-format.txt placeholders descriptions

diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 3622d66488c7de057d32e02cd4cfd21704500822..0c7975a0507a35f9624516f0844ad11cd5141d50 100644 (file)
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -79,6 +79,17 @@ success of the resolution after the custom tool has exited.
        Prompt before each invocation of the merge resolution program
        to give the user a chance to skip the path.
 
+-g::
+--gui::
+       When 'git-mergetool' is invoked with the `-g` or `--gui` option
+       the default merge tool will be read from the configured
+       `merge.guitool` variable instead of `merge.tool`.
+
+--no-gui::
+       This overrides a previous `-g` or `--gui` setting and reads the
+       default merge tool will be read from the configured `merge.tool`
+       variable.
+
 -O<orderfile>::
        Process files in the order specified in the
        <orderfile>, which has one shell glob pattern per line.