meta-google: added details to readme

The README file was effectively empty and now contains the current
information pertaining to the impact of including this layer.

(From meta-google rev: 8b9e630bd4583ef444267099bad768966746bd75)

Change-Id: I90468b99911e5945a4f905084cfab36797e1a3e8
Signed-off-by: Patrick Venture <venture@google.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-google/README.md b/meta-google/README.md
index 379c836..b8d74d7 100644
--- a/meta-google/README.md
+++ b/meta-google/README.md
@@ -1 +1,13 @@
-# meta-google
+# meta-google layer
+
+## Purpose
+
+Including this layer adds the following packages to your `obmc-phosphor-image`:
+
+* [google-ipmi-sys](https://github.com/openbmc/google-ipmi-sys): OEM IPMI Handler for providing specific information to the host.
+* [phosphor-ipmi-blobs](https://github.com/openbmc/phosphor-ipmi-blobs): OEM IPMI Blobs Handler for providing the framework for specific blob handlers.
+* [phosphor-ipmi-ethstats](https://github.com/openbmc/phosphor-ipmi-ethstats): OEM IPMI Handler for reporting ethernet device statistics from the BMCs ethernet devices.
+
+## Customizations
+
+Presently, this layer also enables the Google Iana for registering `phosphor-ipmi-ethstats` in addition to the OpenBMC one.