doc: Import KernelTree process from wiki

Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
diff --git a/doc/process/index.rst b/doc/process/index.rst
index 024518b..a8443ba 100644
--- a/doc/process/index.rst
+++ b/doc/process/index.rst
@@ -4,3 +4,4 @@
 .. toctree::
 
    CONTRIBUTING.md
+   KernelTree.rst