Say git submodule update --init - it's shorter.

bootstrap.sh

@@ -5,5 +5,4 @@ set -e
 aclocal -I m4 --install
 autoreconf -fvi
 
-git submodule init
-git submodule update
+git submodule update --init

docs/source/siteadmin/media-types.rst

@@ -265,8 +265,7 @@ support. This will result in a much smaller list of dependencies.
 
 pdf.js relies on git submodules, so be sure you have fetched them::
 
-    $ git submodule init
-    $ git submodule update
+    $ git submodule update --init
 
 This feature has been tested on Fedora with:
  poppler-utils-0.20.2-9.fc18.x86_64

extlib/README

@@ -114,8 +114,7 @@ FAQ
     Use it just like a snapshotted extlib directory. When a new clone of mediagoblin
     is made you need to run
 
-     git submodule init
-     git submodule update
+     git submodule update --init
 
     As noted in HackingHowto
 

guix-env.scm

@@ -41,8 +41,7 @@
 ;;;   use guix -l guix-env.scm
 ;;;
 ;;; To set things up for the first time, you'll also need to run:
-;;;   git submodule init
-;;;   git submodule update
+;;;   git submodule update --init
 ;;;   ./bootstrap.sh
 ;;;   ./configure --without-virtualenv
 ;;;   make