This topic has come up before and it was mentioned that it may be considered, and there was an appetite for it back in June with the charity bundle, so I thought maybe it's worth mentioning again.

The suggestion is to add options to set a suggested amount, or set amount, that will go directly to charity instead of yourself in the 'Pricing' section of your project.

It could just be itch's monthly picked charity or something like that to start with.