Add a page for quickly adding the field to entities

Copied from [metatag] Metatag

Meta tag field isn't added to CTs automatically in Drupal 8...

With much humbleness, I find it a bit strange that I need to add the Meta tag field to each content type individually... It can take some precious time for sites with many content types and it would be best, I think, to bring back the old D7 way of automatic Metatag field adding to each CT. Or at least --- Each newly generated CT...

I'm a little ambivalent to this request. It feels like something that should be fixed in core, not in contrib. Being able to add fields like this universally doesn't feel like a unique concept to metatags. In the meantime, I do believe that drupal console is doing some work in this space to easily add fields to content types. Perhaps piggy-backing on those efforts is a better path forward, rather than trying to fix a UX problem with a special snowflake that will only help this one module.

I could also be pragmatic and say, go for it and remove the form when one of these other solutions becomes more of a reality.

Examples where someone might want to add a single field, across multiple content types:

• Workflow (a published status field)
• Tagging: a taxonomy term reference (for a site-wide topic/category)
• Date field: (to record when the content was published, not just created or last updated)

I'm sure other cases exist too.