Fix bottom margin of frame location and lack of tab nav

Author: gaearon

packages/react-error-overlay/src/components/frame.js

@@ -120,6 +120,7 @@ function frameDiv(
 
   if (typeof onSourceClick === 'function') {
     let handler = onSourceClick;
+    enableTabClick(frameAnchor);
     frameAnchor.style.cursor = 'pointer';
     frameAnchor.addEventListener('click', function() {
       handler();

packages/react-error-overlay/src/styles.js

@@ -83,6 +83,7 @@ const functionNameStyle = {
 
 const linkStyle = {
   'font-size': '0.9em',
+  'margin-bottom': '0.9em',
 };
 
 const anchorStyle = {