fix problematic HTML caused by certain trailing backslashes

In cases that are **outside of a markdown code block**,
a markdown line with ending in a tailing "\" can generate
problematic HTML.

We certain trailing backslashes outside of a markdown code block
with "<br>" HTML elements, or in some cases eliminated the
need for a trailing backslash.

In a few cases some unnecessary trailing backslashes inside
of a markdown code block were removed.

The following markdown files were changed in this commit:

```
1990/dds/README.md
1990/jaw/README.md
1991/ant/README.md
1991/rince/README.md
1991/westley/README.md
1992/vern/README.md
1992/westley/README.md
1998/schweikh1/README.md
2004/anonymous/README.md
2005/sykes/README.md
2006/toledo2/README.md
2011/toledo/README.md
2012/endoh2/README.md
2012/tromp/README.md
2013/robison/README.md
2015/hou/README.md
2015/howe/README.md
2015/schweikhardt/README.md
2018/burton1/README.md
2018/burton2/README.md
2018/ferguson/README.md
2018/vokes/README.md
2020/ferguson1/README.md
```

Performed `make www` to test these changes.

1991/westley/README.md

@@ -143,16 +143,18 @@ What happens if you make a move already made?
 Now go try and draw or better yet win (without cheating which is very easy :-) )!
 Why is win better than draw? Because everyone knows how to draw:
 
-> Professor Falken: Did you ever play tic-tac-toe?\
-> Jennifer Mack: Yeah. Of course.\
-> Falken: But you don't any more.\
-> Jennifer: No.\
-> Falken: Why?\
-> Jennifer: Because it's a boring game. It's always a tie.\
-> Falken: Exactly. There's no way to win. The game itself is pointless. But back
-at the [International Obfuscated C Code Contest judges'
-room](../../judges.html) they believe that
-you can win tic-tac-toe, that there can be acceptable draws.
+```
+    Professor Falken: Did you ever play tic-tac-toe?
+    Jennifer Mack: Yeah. Of course.
+    Falken: But you don't any more.
+    Jennifer: No.
+    Falken: Why?
+    Jennifer: Because it's a boring game. It's always a tie.
+    Falken: Exactly. There's no way to win. The game itself is pointless.
+	    But back at the International Obfuscated C Code Contest judges'
+	    room they believe that you can win tic-tac-toe, that there can
+	    be acceptable draws.
+```
 
 This is supposed to happen.  As is written in the
 [The Jargon File](http://catb.org/jargon/html/F/feature.html):

1991/westley/index.html

@@ -231,18 +231,16 @@ can lose if you cheat. That’s supposed to happen. Can you win any other time?<
 <p>What happens if you make a move already made?</p>
 <p>Now go try and draw or better yet win (without cheating which is very easy :-) )!
 Why is win better than draw? Because everyone knows how to draw:</p>
-<blockquote>
-<p>Professor Falken: Did you ever play tic-tac-toe?<br />
-Jennifer Mack: Yeah. Of course.<br />
-Falken: But you don’t any more.<br />
-Jennifer: No.<br />
-Falken: Why?<br />
-Jennifer: Because it’s a boring game. It’s always a tie.<br />
-Falken: Exactly. There’s no way to win. The game itself is pointless. But back
-at the <a href="../../judges.html">International Obfuscated C Code Contest judges’
-room</a> they believe that
-you can win tic-tac-toe, that there can be acceptable draws.</p>
-</blockquote>
+<pre><code>    Professor Falken: Did you ever play tic-tac-toe?
+    Jennifer Mack: Yeah. Of course.
+    Falken: But you don&#39;t any more.
+    Jennifer: No.
+    Falken: Why?
+    Jennifer: Because it&#39;s a boring game. It&#39;s always a tie.
+    Falken: Exactly. There&#39;s no way to win. The game itself is pointless.
+            But back at the International Obfuscated C Code Contest judges&#39;
+            room they believe that you can win tic-tac-toe, that there can
+            be acceptable draws.</code></pre>
 <p>This is supposed to happen. As is written in the
 <a href="http://catb.org/jargon/html/F/feature.html">The Jargon File</a>:</p>
 <pre><code>    That&#39;s not a bug, that&#39;s a feature.</code></pre>