[gnome-builder] README: -m gnome-world not needed

[Sébastien Lafargue <slafargue src gnome org>]

commit 1821b4bf3798c934e8687f5c1b78e9b2ff8b1c03
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Wed Oct 28 12:15:00 2015 +0100

    README: -m gnome-world not needed
    
    GNOME Builder is in the apps module set now.

 README |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/README b/README
index 82c72d9..e2fbbed 100644
--- a/README
+++ b/README
@@ -51,7 +51,7 @@ unfamiliar with jhbuild, the following will help you get started.
   ./autogen.sh
   make
   make install
-  jhbuild -m gnome-world build gnome-builder
+  jhbuild build gnome-builder
   jhbuild run gnome-builder
 
 If you have problems building or running Builder, please contact us on IRC