add marker in feed to show where they've seen claims, plus other small clean-up

src/views/StatisticsView.vue

@@ -61,7 +61,7 @@
         <!-- eslint-disable prettier/prettier --><!-- If we format prettier then there is extra space at the start of the line. -->
         <li>Each will show at their time of appearance relative to all others.</li>
         <li>Note that the ones on the left and right edges are randomized
-          because not all their positional data is visible to you.
+          because their data isn't all visible to you.
         </li>
         <!-- eslint-enable -->
       </ul>