I created an express table where I want the user to link out to an external URL. With the current URL attribute the user can input an external URL but its just the raw text (Does not create the a tag and the URL path) I have read the documentation on creating a custom attribute (https://documentation.concrete5.org/developers/attributes/creating-custom-attribute-types/extending-a-core-attribute-type) But I'm still a little bit confused on how to create a custom attribute I can use in my theme package. Does anyone have experience this this.

Thanks