Documentation for creating new feature flags

[QustodioPablo]

I created a PR that was approved and merge but was reverted because it caused breaking changes. It was suggested the fix being implemented with a feature flag.
Is there any documentation about whats the process for adding a new feature flag? I'm honestly lost on this regard.

Thanks!

[peterwoodworth]

We have a section in our contributing guide here, let us know if there's anything we can do to make this more clear!

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.