Option to make "Weasel Project:" in the generated README optional?

Hello! 😄

Feature request: is it possible to make the [`Weasel Project:` tag in the README](https://github.com/explosion/weasel/blob/main/weasel/cli/document.py#L59) optional? I have a use-case where the added word can cause some confusion to other devs especially if they're not yet familiar with the library. I know that I can always edit the README to remove this, but wondering if I can set a flag instead.

Would still love to have an indication that the project was generated by weasel, so perhaps as an alternative, we can put it in the footer instead? Or maybe a short sentence after the title.

Thanks and have a great day!