Update documentation.

Change-Id: Idb03741fab9facbbbda85d5a82723f0b4c1c6c60
diff --git a/README b/README
index 14fd355..14be3fe 100644
--- a/README
+++ b/README
@@ -1,3 +1,3 @@
 Ceres Solver - A non-linear least squares minimizer
 ==================================================
-Please see ceres-solver.pdf in docs/ for a tutorial and reference.
+Please see docs/html/index.html for a tutorial and reference.