[Let`s go with golang] Simple Factory

I learn use interface, so it`s time to factory.
As if someone didn't know what a factory is:
https://en.wikipedia.org/wiki/Factory_(object-oriented_programming)

Simple of course-> write text to output or file.

https://github.com/mikoxp/Go_code/cohttps://github.com/mikoxp/Go_code/commit/ce3ba7f41c447be302e63bccb04a05392d1516ab