Add canonical url support

[mattw0110]

Add a self-referencing canonical URL and an option in the writer to assign another URL if needed.

[avitorio]

Hey @mattw0110, thanks for the suggestion.

The canonical url should be set on the frontend.

For custom canonical urls, you could create a custom field and check if it has been populated. If not just use the actual page url.

Let me know if this works or if you need any help with it.

[mattw0110]

Worked Great!