Fix image link.

Change-Id: Iae8548c3aa7379f043be3318e59ed39b531e2f07
Reviewed-on: https://swiftshader-review.googlesource.com/5440
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
diff --git a/docs/Index.md b/docs/Index.md
index dea6100..c59a84c 100644
--- a/docs/Index.md
+++ b/docs/Index.md
@@ -12,7 +12,7 @@
 

 Structurally there are four major layers:

 

-![API, Renderer, Reactor, JIT](./ArchitectureLayers.png "Architecture Layers")

+![API, Renderer, Reactor, JIT](/docs/ArchitectureLayers.png "Architecture Layers")

 

 The API layer is an implementation of a graphics API, such as OpenGL (ES) or Direct3D, on top of the Renderer interface. It is responsible for managing API-level resources and rendering state, as well as compiling high-level shaders to bytecode form.