Document the registry enhancements pattern

[stacey-gammon]

The "registry enhancements" pattern is something that is happening more frequently. It started out with SavedObjectClient and security enhancing it. Since then, embeddables has taken this approach, and uiActions is starting to as well.

I started to create a recipe for this pattern here: #62998. An example would be useful because there are important considerations to take into account when following this pattern, like tacking extra state on in a specific way so that state can be migrated properly (#62950)

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[streamich]

Closing this as with the recent license changes I understand we will use this pattern way less.