[Feature/Enhancement] Display the Notebook List after opening a directory of markdown documents

[fyodorovich]

Enhancement / feature description: When I open a folder of documents I want to see the immediate result of my action. For me, the most obvious result is to see the list of documents displayed in the Notebooks pane.

I want to be able to select the document which I will work on. I do not expect to have one of the documents selected and opened for me. Users who open folders of markdown for reading ( rather than editing ) may prefer the current behaviour, so it could be an option.