How to share credentials

[aleksa-krolls]

This comes up a lot on projects... we should either add docs to explain that this can't be done on the app (and that credentials must be re-created if you want a different user to see the creds).

Or hopefully a feature will come where it will be possible to transfer ownership of credentials.

What we have now on creds:

1. https://docs.openfn.org/documentation/build/credentials
2. https://docs.openfn.org/documentation/user-credentials