[Converters\define] add documentation example for `.as`

[github-actions[bot]]

[Converters\define] add documentation example for .as

https://github.com/arturo-lang/arturo/blob/7e2f1bee9a5648466ae75dbdd238ce56338f051a/src/library/Converters.nim#L530

            "methods"   : {Block}
        },
        attrs       = {
            "as"    : ({Type}, "inherit given type")
        },
        returns     = {Nothing},
        # TODO(Converters\define) add documentation example for `.as`
        #  labels: library, documentation, easy
        example     = """
            define :person [name surname age][  

24aaea2dd5e887554c24d214d02ea2ffb05ee457

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[drkameleon]

To be postponed until the usage of .as is (properly) defined. 🤔