Min + max block types in matrix fields

[josh-attwood]

It would be great to have some function to limit the number of times a block type can be added to a matrix field.

For example we have a site where we'd like a certain block to always be shown on the homepage but would give the user the ability to choose its position and would like to make sure it only shows up once. In that scenario we'd set the min and max to 1. This is something I've used in the past when developing in Wordpress + ACF which was very useful.

[brandonkelly]

Thanks for posting! This was previously requested over at #8596. You can follow along over there for updates.