Include Examples of Multi-interface Restricted Types

[dete]

Issue to be solved

The Cadence reference pages for restricted types and capabilities use examples with a single interface as part of the restriction to make things clear. I think it would be useful to include a note that explicitly says that multiple interfaces are allowed, and shows a simple, extended example with multiple interfaces as part of a restricted type.

Suggested Solution

No response

[turbolent]

Can close once onflow/flips#85 is approved and implemented

[j1010001]

Add example for interface sets with multiple interfaces.

[dsainati1]

I believe the new documentation actually already has this: https://developers.flow.com/next/cadence/language/intersection-types