Add a JSON to seek funding from the FLOSS/fund

[ericwb]

The FLOSS/fund is running a program to invest support in critical, impactful, and valuable open source projects.

Adding this file doesn't guarantee funding, but raises awareness Bandit is seeking it.

The JSON has been validated using their online validation tool: https://dir.floss.fund/validate

More info: https://floss.fund/blog/announcing-floss-fund/