GET <baseurl>/api/v1/collections/<collname>/items/<id>
GET <baseurl>/api/v1/collections/<collname>/items/<url-slug>

This is the equivalent of API end-point "Retrieve a Post" to get an item with any type.

Used for:

• Display item content in modal window of merging posts
• Display item content in modal window of inserting short link by Short Links / ForeverLinks / Quick Links Plugin