README.md: Add flow chart diagram.

Move "Graphyte Flow.png" to doc/images and have it displayed in
README.md.

BUG=None
TEST=None

Change-Id: Ia3c925500ec9b985508b0f2437b5f20a87d9676c
Reviewed-on: https://chromium-review.googlesource.com/1063850
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Shen-En Shih <petershih@chromium.org>
diff --git a/README.md b/README.md
index 86943c7..f33f71e 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,8 @@
 Please refer to the [user manual](https://groups.google.com/forum/#!topic/graphyte-public/GJgiDc482K8)
 for more details.
 
+![Flow chart](doc/images/graphyte_flow.png)
+
 ## Build
 No build step is required.
 
diff --git a/Graphyte Flow.png b/doc/images/graphyte_flow.png
similarity index 100%
rename from Graphyte Flow.png
rename to doc/images/graphyte_flow.png
Binary files differ