Add FUNDING file (#1099)
This file copied from the servo repo indicates that financial support
for rust-url should be directed to the Servo project, via:
* [GitHub Sponsors](https://github.com/sponsors/servo), or
* [Open Collective](https://opencollective.com/servo)
See [GitHub documentation](https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/displaying-a-sponsor-button-in-your-repository).
This file is notably read by [ecosyste.ms](https://ecosyste.ms/),
whose [Rust Ecosystem Fund](https://funds.ecosyste.ms/funds/rust)
already has donations allocated to rust-url.
Donations are made to the fund as a whole,
which then distributes to popular crates based on some weighing function.
Although rust-url was originally created for use in Servo
it is also used in many other projects and exits independently.
However at this point rust-url is neither a mostly-single-person project,
nor does it have its own formal structure capable of managing a budget.
So if not Servo, it’s not clear to me where this money should go.
The status quo is that money allocated to rust-url by ecosyste.ms
remains unclaimed. For February 2026, that amount is $93.67.
[ecosyste.ms says](https://funds.ecosyste.ms/faq):
> Unclaimed funds are redistributed the following month.
… but the details of that are not clear to me. As of this writing the
[Rust Ecosystem Fund](https://funds.ecosyste.ms/funds/rust) page
shows almost $21k collected (presumably USD, over its lifetime)
but less then $15k actually distributed to projects.
Simon Sapin