Add architecture documentation.

Change-Id: Ie28d3e61fda6fa01f5dc669a4ef3f4c0b09743d0
Reviewed-on: https://swiftshader-review.googlesource.com/5430
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
diff --git a/README.md b/README.md
index 71c4b4e..be93bca 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,11 @@
 

     git push origin HEAD:refs/for/master

 

+Documentation

+-------------

+

+See (docs/Index.md)[docs/Index.md].

+

 Contact

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