[pygobject] docs/getting started: add "pacman -Suy" before installing packages under msys2

[Christoph Reiter <creiter src gnome org>]

commit 692f32364c2f23efe3cc16bef77cb22a1103cbb3
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Wed May 16 20:21:45 2018 +0200

    docs/getting started: add "pacman -Suy" before installing packages under msys2
    
    pacman doesn't support installing packages without doing a system upgrade
    first. In case the user already has msys2 installed but not used in a while
    just doing the install might not work.

 docs/getting_started.rst | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/docs/getting_started.rst b/docs/getting_started.rst
index 4cee81af..eabde650 100644
--- a/docs/getting_started.rst
+++ b/docs/getting_started.rst
@@ -36,13 +36,14 @@ and their dependencies. Follow the instructions for your platform below.
 |windows-logo| Windows
 ----------------------
 
-1) Go to http://www.msys2.org/ and download the x86_64 installer
-2) Follow the instructions on the page for setting up the basic environment
-3) Run ``C:\msys64\mingw32.exe`` - a terminal window should pop up
-4) Execute ``pacman -S mingw-w64-i686-gtk3 mingw-w64-i686-python2-gobject mingw-w64-i686-python3-gobject``
-5) To test that GTK+3 is working you can run ``gtk3-demo``
-6) Copy the ``hello.py`` script you created to ``C:\msys64\home\<username>``
-7) In the mingw32 terminal execute ``python3 hello.py`` - a window should appear.
+#) Go to http://www.msys2.org/ and download the x86_64 installer
+#) Follow the instructions on the page for setting up the basic environment
+#) Run ``C:\msys64\mingw32.exe`` - a terminal window should pop up
+#) Execute ``pacman -Suy``
+#) Execute ``pacman -S mingw-w64-i686-gtk3 mingw-w64-i686-python2-gobject mingw-w64-i686-python3-gobject``
+#) To test that GTK+3 is working you can run ``gtk3-demo``
+#) Copy the ``hello.py`` script you created to ``C:\msys64\home\<username>``
+#) In the mingw32 terminal execute ``python3 hello.py`` - a window should appear.
 
 .. figure:: images/start_windows.png
     :scale: 60%