Support `test this in binder`

[GeorgianaElena]

Description

We should add a GitHub action to this template that automatically provides a "test on Binder" comment to new Pull Requests.

Benefit

This would allow others to quickly test out images to make sure things are updated as expected (and, to make sure that an environment actually builds!)

Implementation

The peddie image has a good example of this workflow in action: https://github.com/2i2c-org/peddie-image/blob/main/.github/workflows/binder.yaml

(Originally posted in 2i2c-org/infrastructure#493 (comment))