Support rendering of plugins

[almereyda]

What Happened?

As a LogSeq user, I need to produce a static rendering of my graph including all plugins and themes #8, in order to be able to reproduce the interfaces that are made available through the graph data.

Reproduce the Bug

1. Create a static export from a graph that uses the Sepia theme together with the Kanban plugin.
2. See both not being available in the output.

Expected Behavior

The theme and plugin are available in the output.

[almereyda]

It has been stated in #8 (comment) that plugins are currently technically not possible.

This issue documents reasons why this is the case at the moment and suggests paths of resolution moving onward.