Adds a Credits section to README + adds myself

Feels hokey/lame to do this, but doing it anyway! 😅

Author: Gowiem

README.md

@@ -1,3 +1,7 @@
 # getgif
 
 An Example Golang CLI app using the FusionAuth Golang Client Library to provide Device Code OAuth
+
+## Credits
+
+- [@Gowiem](https://github.com/Gowiem) / [@masterpointio](https://github.com/masterpointio) for the initial implementation and blog post!