Document how to trigger a block refresh programatically

Problem/Motivation

Hi and thank you for this great and super helpful module!

Based on #3351439: Impossible to trigger a refresh it would be great to have a documentation how to trigger the reload of a certain ajax block programmatically.
Even better would be to have a convenient JS Public API method?

What do you think?

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes