Entity Share - support folks and document setup process

[finnlewis]

This has bubbled up again in Slack.

A fair few folks use Entity Share to deploy content.

Some also use Config Split to avoid having the Entity Share Server enabled on the production site.

I want to get a better handle on this and document how to use it for others.

[willguv]

We need to bear in mind the content staging conversation in Drupal Slack

[willguv]

Entity Share was covered by Cumbria when they started using it https://cumbria.localgov.blog/2022/05/31/using-entity-share-with-localgov-drupal/