Allow making workspace veeery small

Author: Ives van Hoorne

packages/app/src/app/pages/Sandbox/Editor/index.js

@@ -55,6 +55,7 @@ function ContentSplit({ signals, store, match }) {
             <SplitPane
               split="vertical"
               defaultSize={sandboxOwned ? 16 * 16 : 18 * 16}
+              minSize={0}
               onDragStarted={() => signals.editor.resizingStarted()}
               onDragFinished={() => signals.editor.resizingStopped()}
               resizerStyle={{