Updated CHANGELOG and added csharp/README.md

Author: GlitchedPolygons

CHANGELOG

@@ -9,4 +9,5 @@ that I've applied, in order of importance/relevance:
 * Added CMakeLists.txt and build.sh for easy packaging and inclusion into other projects.
 * Deleted .dll files inside repo.
 * Adapted readme.md accordingly.
+* Implemented C# wrapper class.
 * Added this CHANGELOG file.

csharp/README.md

@@ -0,0 +1,5 @@
+# C# wrapper class for orlp-ed25519
+
+In order to use this, just copy the [`OrlpEd25519Context`](https://github.com/GlitchedPolygons/GlitchEd25519/blob/master/csharp/OrlpEd25519.cs) 
+class into your own C# project and manually copy the [`lib/`](https://github.com/GlitchedPolygons/GlitchEd25519/tree/master/csharp/lib) folder into your
+own project's build output directory (otherwise the `OrlpEd25519Context` wrapper class doesn't know where to load the DLL/shared lib from; it needs to be in that specific path).