po: add Irish translation (#3256)

Author: aindriu80

docs/i18n.md

@@ -69,6 +69,7 @@ Some of the languages Solaar has been translated to are listed below. A full lis
 - Turkish: Osman Karagöz
 - Ukrainian: Олександр Афанасьєв
 - Bulgarian Николай Йорданов
+- Irish: Aindriú Mac Giolla Eoin
 
 [Rongronggg9]: https://github.com/Rongronggg9
 [papoteur]: https://github.com/papoteur