so we have the split preview today (edit in one window, preview in another). vscode supports combining the two using either webviews or custom editors. you can

so we have the split preview today (edit in one window, preview in another). vscode supports combining the two using either webviews or custom editors. you can see an example of that here -> https://github.com/tejasvi/markless https://github.com/tejasvi/markless we're planning on implementing a similar featureset