add funding info (#44)

Author: danieleades

.github/FUNDING.yml

@@ -0,0 +1,2 @@
+issuehunt: danieleades
+github: danieleades

README.md

@@ -14,4 +14,6 @@ Take a look at the  [API docs](https://docs.rs/arithmetic-coding/) or the [examp
 This crate is heavily inspired by
 
 - [arcode-rs](https://github.com/cgburgess/arcode-rs)
-- [Data Compression With Arithmetic Coding - *Mark Nelson*, 2014](https://marknelson.us/posts/2014/10/19/data-compression-with-arithmetic-coding.html)
+- [Data Compression With Arithmetic Coding - *Mark Nelson*, 2014](https://marknelson.us/posts/2014/10/19/data-compression-with-arithmetic-coding.html)
+
+*Was this useful? [Buy me a coffee](https://github.com/sponsors/danieleades/sponsorships?sponsor=danieleades&preview=true&frequency=recurring&amount=5)*