allow for .txt files too b/c github doesn't allow .json attachments

Author: David Blackman

docs/compare.html

@@ -280,7 +280,7 @@
     <div id="header"></div>
     <div id="scoreboardContainer">
       <div id="scoreboard"></div>
-      <input id="jsonFileInput" type="file" accept="application/json" style="display: none;" />
+      <input id="jsonFileInput" type="file" accept="application/json, text/plain" style="display: none;" />
       <button id="load">Load</button>
       <button id="save">Save</button>
     </div>