Update README.md

Author: JoeStrout

README.md

@@ -4,3 +4,8 @@ This project contains the source code of both C# and C++ implementations of the
 
 
 
+## Sponsor Me!
+
+MiniScript is free, and apart from a small amount of revenue from the [books](https://miniscript.org/books/) and [Unity asset](https://assetstore.unity.com/packages/tools/integration/miniscript-87926), generates no significant income.  Your support is greatly appreciated, and will be used to fund community growth & reward programs like [these](https://miniscript.org/earn.html).
+
+So, [click here to sponsor](https://github.com/sponsors/JoeStrout) -- contributions of any size are greatly appreciated!