docs: add note on return value sizes in interfaces

[pcaversaccio]

Add a note in the interface documentation regarding the following fact:

If we use interfaces via Vyper syntax, the following holds: For any input parameters, where you have to put a max threshold (eg. dynamic arrays, strings, bytes etc). the values defined in the interface reflect also the max threshold in the implementation. However, for any return values, if you need to define a max threshold in the interface, it reflects the lower bound in the implementation.

[pcaversaccio]

I will take care of this issue and will submit a PR.

[charles-cooper]

note that we are planning to remove explicit bounds in interfaces in favor of ellipses quite soon - see #2814 (comment)

[pcaversaccio]

note that we are planning to remove explicit bounds in interfaces in favor of ellipses quite soon - see #2814 (comment)

That's why I write in the PR 'This behaviour might change in the future.' You want me to add something else?

[charles-cooper]

That's why I write in the PR 'This behaviour might change in the future.' You want me to add something else?

no! just wanted to give a heads up to anybody following this issue.