ktest: Add README to explain what is in the examples directory

Add a README that explains what the different example configs in the
ktest example directory are about.

Signed-off-by: Steven Rostedt <[e-mail]>

tools/testing/ktest/examples/README

···
+This directory contains example configs to use ktest for various tasks.
+The configs still need to be customized for your environment, but it
+is broken up by task which makes it easier to understand how to set up
+ktest.
+
+The configs are based off of real working configs but have been modified
+and commented to show more generic use cases that are more helpful for
+developers.
+
+crosstests.conf - this config shows an example of testing a git repo against
+    lots of different architectures. It only does build tests, but makes
+    it easy to compile test different archs. You can download the arch
+    cross compilers from:
+  http://kernel.org/pub/tools/crosstool/files/bin/x86_64/
+
+test.conf - A generic example of a config. This is based on an actual config
+     used to perform real testing.
+
+kvm.conf - A example of a config that is used to test a virtual guest running
+     on a host.
+
+snowball.conf - An example config that was used to demo ktest.pl against
+     a snowball ARM board.
+
+include/  -  The include directory holds default configs that can be
+    included into other configs. This is a real use example that shows how
+    to reuse configs for various machines or set ups. The files here
+    are included by other config files, where the other config files define
+    options and variables that will make the included config work for the
+    given environment.
+
+