[Scoped Slots][Doc] Update error message about directives usage restriction to point to external documentation.

[ravijayaramappa]

Description

<slot> elements are allowed to use only lwc:data-bind directive and no other directives. The restriction error message contains a list of all directives that are forbidden. The documentation for scoped slots should contain this restriction with the list of directives.

This bug is to update the error message to an external documentation page.

Additional details:
#3077 (comment)

GUS work Item
W-11889911