Add illustration to Chapter 21

Author: marijnh

21_skillsharing.txt

@@ -24,6 +24,8 @@ meetings moved to another town, nobody stepped forward to take over
 this task. We want a system that will let the participants propose and
 discuss talks among themselves, without a central organizer.
 
+image::img/unicycle.svg[alt="The unicycling meetup"]
+
 (!html Just like in the link:20_node.html#node[previous chapter], the
 code in this chapter is written for Node.js, and running it directly
 in the HTML page that you are looking at is unlikely to work. !)The

html/index.html

@@ -25,12 +25,12 @@ <h1>Eloquent JavaScript<div style="font-size: 70%">second edition</div></h2>
   may also be considered licensed under
   an <a href="http://opensource.org/licenses/MIT">MIT license</a>.</p>
 
-  <p style="font-size: 80%">Illustrations by various artists: Cover by Wasif Hyder. Computer
-  (introduction) by Max Xiantu. Sea of bits (Chapter 1) and
-  weresquirrel (Chapter 4) by Margarita Martínez and José Menor.
-  Octopuses (Chapter 2 and 4) by Jim Tierney. Object with on/off
-  switch (Chapter 6) by Dyle MacGregor. Regular expression diagrams in
-  Chapter 9 generated
+  <p style="font-size: 80%">Illustrations by various artists: Cover by
+  Wasif Hyder. Computer (introduction) and unicycle people (Chapter
+  21) by Max Xiantu. Sea of bits (Chapter 1) and weresquirrel (Chapter
+  4) by Margarita Martínez and José Menor. Octopuses (Chapter 2 and 4)
+  by Jim Tierney. Object with on/off switch (Chapter 6) by Dyle
+  MacGregor. Regular expression diagrams in Chapter 9 generated
   with <a href="http://regexper.com">regexper.com</a> by Jeff
   Avallone. Game concept for Chapter 15
   by <a href="http://lessmilk.com">Thomas Palef</a>. Pixel art in