Requested feature overview description.

Add a line of text on the Pool Import page to show how to import a specific post by its id, with id:postnumber being the syntax.

Why would it be useful?

It may not be clear to newer users who are expanding pools that it's possible to use metadata to search for a single post. Clarifying this with a line of text would help educate users and expedite the process of altering pools using that knowledge.

What part(s) of the site page(s) are affected?

The Pool Import page.