Update URL field description text, or relax URL validation rules for resources

[jhung]

Is your feature request related to a problem? Please describe.

With the ACF URL field, it requires http:// or 'https://`, otherwise the form will not validate and an error is shown. This can be confusing as the URLs may be "valid" and the instructions do not indicate the necessary formatting.

Describe the solution you'd like

Preferred solution is to add http:// or https:// if it is missing from the input upon form submission.

Easy solution, but more of a burden for the user, is to update the description string to indicate that https:// or http:// prefix is required. The resulting error message should also display a helpful instruction as well.