[feature request] Allow theme selection per diagram

[jasal82]

The theme should be selectable on a per-diagram basis, e.g. by adding a preamble to the d2 code block which contains the settings and is then removed by the plugin before forwarding it to d2.

[alixander]

Right. This is built into D2, but I think the Obsidian plugin hasn't been updated to pick those up. Will do, thanks!

https://d2lang.com/tour/vars/#configuration-variables

[eriktalvi]

If all the config-variables could be used . I'm looking at the layout-engine variable specifically.