Incomplete interface for validate in NgxLinkifyOptions

[teolag]

The interface for validate in NgxLinkifyOptions is incomplete.

ngx-linkifyjs/src/module/interfaces/ngx-linkifyjs.interface.ts

Line 21 in 254d6d6

validate?: boolean,

According to linkifyjs the validate attribute could be a boolean, function or an object
https://soapbox.github.io/linkifyjs/docs/options.html#validate

When I set validate to a function the linter typescript warns me I'm using the wrong type.
If I set the function as any, everything works fine. So the code accepts an function but the interface does not

[AnthonyNahas]

I would appreciate a PR from you🍻