remote: add promisor and partial clone config to the doc

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 877e5f503a66145912886c14917f0e68512e6284..964f912d29ee92d55a3c98d40cc41941e7db743a 100644 (file)
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -313,6 +313,10 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 <start_point>::
        The name of a commit at which to start the new branch; see
        linkgit:git-branch[1] for details. Defaults to HEAD.
++
+As a special case, you may use `"A...B"` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 <tree-ish>::
        Tree to checkout from (when paths are given). If not specified,