Automatically crop export PNG to content

[yinchi]

Is your feature request related to a problem? Please describe. Currently exporting a diagram as a PNG exports the entire canvas even when only a small part of it is used.

Describe the solution you'd like An option to automatically crop to the visible content area when exporting a PNG.

Describe alternatives you've considered I can crop the image with another software tool after exporting, but this takes time.

[dmohns]

Adding to this request, it would also be great if we add additional PNG export options, like transparent background.