Update authors.md

Author: Costas Korai

AUTHORS.md

@@ -25,6 +25,7 @@
 - Abhishek Saini - <https://github.com/Abhisheksainii>
 - Hanaa Allohibi - <https://github.com/hn-n>
 - Shey Alnasrawi - <https://github.com/Milksheyke>
+- Costas Korai - <https://github.com/watcher6280>
 
 ## Translators