@jaynus

From Discord conversation regarding alternative destinations (image, video, memory buffer) for rendy graphs, we need an example of rendering screenshots through rendy.

We want to make sure that everything supports text descriptions, which can be used when scaffolding front end layers and building documentation.

Right now, every time we add an expression we count the bindings, see filter_value_to_expr in data_layer.ex. We should just keep track of the count alongside the list.