Use Google Docs Inside of DEVONthink
For bookmarks DEVONthink shows the linked web page immediately when you select it in any view that has a preview pane, e.g. in Split view. And as Google Docs is just a web page you can add it to DEVONthink just like any other bookmark. Select it and DEVONthink shows the complete Google Docs editor just like as if it was a local document.