Additional tags - self-produce assets on-load

[psychemedia]

If we use this as an OU tagstyler, there are other things it may be useful to apply.

For example, if we tag something as "production-flowchart" then we could maybe:

• hide the input cell;
• autorun the cell on notebook start to display the result and then freeze it / make it no longer runnable.

This means we start to think of the document as a self-producing document on load?