Custom viewer UI for certain markdown files

[rigmarole]

@cybrox

can’t post links.

Now you can.

The link you wanted to post:

Creating a viewer for a custom file type--jupyter

Thanks. Is the data property then the JSON contents of the file? And the idea would be that my implementation of the abstract method setViewData(data, clear) would do my transformation to HTML, walk the workspace tree to the current tab, and call createEl on something?