Add more in the README

Author: nicolasstucki

README.md

@@ -4,3 +4,13 @@
 
 This is a normal sbt project, you can compile code with `sbt compile` and run the tests
 with `sbt test`.
+
+### Exercise
+
+Implement optimizations for a simple dot product on arrays where the arrays may be statically known.
+`src/main/scala/Vectors` already implments the a `dot` product using a macro. The implmentation is in the method `dotImpl` which already optimizes for two statically known empty vectors. Your task is to add more optimizations
+based on statically known information that can be recovered through the TASTy reflect API.
+
+### TASTy relfect
+
+TASTy reflect is mostly based on extractors. Using the show method on trees will show the extractors required to pattern match on it. Some examples are shown in the code.