[Benchmark] Edit readme to include where this is from.

Change-Id: I17c4e226613267da325fdc153b1dffe3f55bf0e3
diff --git a/README.md b/README.md
index bbe2a52..867130e 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,9 @@
+This is a fork of https://github.com/google/iosched in order to use this project as a benchmark
+for the Android Gradle plugin.
+Changes made to the project to run the benchmark as prefixed by [Benchmark]
 Google I/O Android App