I would like to donate the PostHog OpenFeature provider

[weyert]

Description

After forking some of my other PostHog related work. I would like to donate the OpenFeature provider to PostHog. As it's a great benefit to PostHog to support OpenFeature and I think it's best for the vendor to maintain than a single maintainer:
https://github.com/Tapico/node-posthog-openfeature

I also have a non-public version of the OpenFeature provider for the web.

[marandaneto]

cc @PostHog/team-feature-flags