Get rid of counter reset in title list

Since it triggers a bug in Firefox 82

Issue marijnh#535

Author: marijnh

epub/toc.xhtml.src

@@ -42,7 +42,7 @@
     <!-- user-visible TOC -->
     <ol class="toc">
       <li class="no-number"><a href="00_intro.xhtml">Introduction</a></li>
-      <li style="counter-reset: li; position: relative">
+      <li style="position: relative">
         <a href="01_values.xhtml"><span class="parttitle">(Part 1: Language)</span>Values, Types, and Operators</a>
       </li>
       <li><a href="02_program_structure.xhtml">Program Structure</a></li>

html/index.html

@@ -74,7 +74,7 @@ <h2>Contents</h2>
 
   <ol class=toc>
     <li class="contents-intro"><a href="00_intro.html">Introduction</a>
-    <li style="counter-reset: li">
+    <li>
       <h3>(Part 1: Language)</h3>
       <a href="01_values.html">Values, Types, and Operators</a>
     </li>