create polish locale file

[Kurczaczki69]

Description

I have added the polish locale to the plugin. Please tell if i need to do anything else to add it other than making the yml file

Changes

Created a locale file called pl.yml with messages localized to the polish language

Related Issues

none

Checklist

• [x] I have fully tested the proposed changes and promise that they will not break everything into chaos.
• [x] I followed the existing code standards and didn't mess up the formatting.
• [x] I did my best to add documentation to any public classes or methods I added.