app opens in edit mode if there is only one revision

src/container/HtmlDocument.jsx

             }))
           ], [])
 
-        this.setState({timeline: revisionWithComment})
+        this.setState({
+          timeline: revisionWithComment,
+          mode: resRevision.body.length === 1 ? MODE.EDIT : MODE.VIEW // first time editing the doc, open in edit mode
+        })
       })
       .catch(e => {
         console.log('Error loading Timeline.', e)