Install git.mk in docs/
diff --git a/docs/Makefile.am b/docs/Makefile.am
index f3ddc22..034926c 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -1 +1,3 @@
 SUBDIRS = reference
+
+-include $(top_srcdir)/git.mk