[recipes] Fix build instructions in README.md

[Matthew Leeds <mwleeds src gnome org>]

commit 9efd302f41f8428eb1204ed62bd0c95b0b4b2399
Author: Matthew Leeds <mleeds redhat com>
Date:   Wed Feb 22 11:43:35 2017 -0600

    Fix build instructions in README.md
    
    Recipes needs a recursive clone so libgd will be checked out.

 README.md |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/README.md b/README.md
index fbca84a..650d77b 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ apt install autoconf-archive gobject-introspection libjson-glib-dev libgnome-aut
 To build GNOME Recipes from git, use the following steps:
 
 ```
-git clone git://git.gnome.org/recipes
+git clone --recursive git://git.gnome.org/recipes
 cd recipes
 ./autogen.sh --prefix=<your preferred location>
 make