Link benchmarking docs from the doc main page

docs/Readme.md

@@ -14,6 +14,7 @@ Writing tests:
 * [Event Listeners](event-listeners.md#top)
 * [Data Generators](generators.md#top)
 * [Other macros](other-macros.md#top)
+* [Micro benchmarking](benchmarks.md#top)
 
 Fine tuning:
 * [Supplying your own main()](own-main.md#top)

docs/benchmarks.md

@@ -1,3 +1,4 @@
+<a id="top"></a>
 # Authoring benchmarks
 
 Writing benchmarks is not easy. Catch simplifies certain aspects but you'll