[gnome-builder] doc: add a blurb about processes section

[Christian Hergert <chergert src gnome org>]

commit 589606b6512330a3fb55664ff92c30feae09e5cc
Author: Christian Hergert <chergert redhat com>
Date:   Wed Mar 15 14:01:38 2017 -0700

    doc: add a blurb about processes section

 doc/plugins/processes/index.rst |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/doc/plugins/processes/index.rst b/doc/plugins/processes/index.rst
index 8425614..9d87de2 100644
--- a/doc/plugins/processes/index.rst
+++ b/doc/plugins/processes/index.rst
@@ -2,6 +2,10 @@
 Processes and Containers
 ########################
 
+Builder needs to support a wide variety of ways to spawn processes.
+Whether that is inside a build environment, container, on the host, terminals, or even a remote system.
+The following sections describe some of the scenarios and how to best perform the task at hand.
+
 .. toctree::
    :maxdepth: 3
    :titlesonly: