Preview mode for new tabs

I would like my tabs to open in preview mode when I single click a file.

Only if I save, edit, or double click a file do I want the tab to stay open.

Is there a way to do this?

VSCode does this by default, why can’t Mbed Studio be the same?

Essentially, what this extension does:

Is there a way to install extensions?
I tried several ways including the npm install route, but just feels like it’s over-complicated for just adding a simple extension.