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.

2018/ferguson/README.md

@@ -223,7 +223,7 @@ monkey; I thought the monkey had it too easy: unlike his limited keyboard I have
 `isprint()` returns non-zero except that only capital letters are included;
 the file [prog.alt.c](prog.alt.c) has a slightly smaller keyboard. There are some
 additional features I have added (including two Easter eggs); amongst others:
-ability to change the target string and maximum length. See\
+ability to change the target string and maximum length. See
 **[How it works](#how)**, **[Hints](#hints)** and **[How to build](#build)** for
 more details.
 
@@ -465,8 +465,8 @@ If you do one of:
 ```
 
 It will search for `MONKEY` in both cases; in other words it's the last one.
-If the string is too long given the value of `S` (see\
-**[How to build](#build)**) it will be truncated.
+If the string is too long given the value of `S` (see **[How to build](#build)**)
+it will be truncated.
 
 If you actually do want to search for a string starting with a `-` you must
 disable further parsing of options by using the `-` option itself; for
@@ -492,7 +492,7 @@ examples of the last set of three above are equivalent i.e. the following two
 are equivalent:
 
 ```
-    -q-\
+    -q-
     -q --
 ```
 
@@ -735,7 +735,7 @@ people. Take the following invocations:
     (1) $ echo test > test
     (2) $ ./weasel test
     (3) $ ./weasel < test
-    (4) $ cat test | ./weasel\
+    (4) $ cat test | ./weasel
     (5) $ < test-strings.txt ./weasel
     (6) $ cat | ./weasel
 ```
@@ -819,7 +819,7 @@ Skip to [Obfuscation](#obfuscation).
 
 There is a type of input error, as I said, that might appear to be a bug. What
 actually is going on though is due to a technicality on how spaces are printed
-and the fact the program does not accept spaces other than a literal space\
+and the fact the program does not accept spaces other than a literal space
 ` `; when a character in the string to be found isn't in the keyboard the
 program prints an error message and then exits (returning 1). But since the
 keyboard doesn't have `'\n'` if you were to type a `'` and send a

2018/ferguson/index.html

@@ -305,7 +305,7 @@ monkey; I thought the monkey had it too easy: unlike his limited keyboard I have
 <code>isprint()</code> returns non-zero except that only capital letters are included;
 the file <a href="prog.alt.c">prog.alt.c</a> has a slightly smaller keyboard. There are some
 additional features I have added (including two Easter eggs); amongst others:
-ability to change the target string and maximum length. See<br />
+ability to change the target string and maximum length. See
 <strong><a href="#how">How it works</a></strong>, <strong><a href="#hints">Hints</a></strong> and <strong><a href="#build">How to build</a></strong> for
 more details.</p>
 <p>In its simplest invocation this program will work its way (using a genetic
@@ -481,8 +481,8 @@ specially by your shell e.g. parentheses. For instance if you just want to find
 <pre><code>    ./weasel &quot;METHINKS IT IS A&quot; &quot;MONKEY&quot;
     ./weasel METHINKS IT IS A MONKEY</code></pre>
 <p>It will search for <code>MONKEY</code> in both cases; in other words it’s the last one.
-If the string is too long given the value of <code>S</code> (see<br />
-<strong><a href="#build">How to build</a></strong>) it will be truncated.</p>
+If the string is too long given the value of <code>S</code> (see <strong><a href="#build">How to build</a></strong>)
+it will be truncated.</p>
 <p>If you actually do want to search for a string starting with a <code>-</code> you must
 disable further parsing of options by using the <code>-</code> option itself; for
 example if you were to do any of:</p>
@@ -497,7 +497,7 @@ longer parse additional options: only target strings if anything left on the
 command line. Because of the joining of arguments this means that the first two
 examples of the last set of three above are equivalent i.e. the following two
 are equivalent:</p>
-<pre><code>    -q-\
+<pre><code>    -q-
     -q --</code></pre>
 <p>As for the caveat I referenced what does the following do?</p>
 <pre><code>    ./weasel -qr 5</code></pre>
@@ -660,7 +660,7 @@ people. Take the following invocations:</p>
 <pre><code>    (1) $ echo test &gt; test
     (2) $ ./weasel test
     (3) $ ./weasel &lt; test
-    (4) $ cat test | ./weasel\
+    (4) $ cat test | ./weasel
     (5) $ &lt; test-strings.txt ./weasel
     (6) $ cat | ./weasel</code></pre>
 <p>Only the first invocation of <code>./weasel</code> will search for <code>TEST</code> because
@@ -718,7 +718,7 @@ example shows (but the strings will still only be read from the
 <p>Skip to <a href="#obfuscation">Obfuscation</a>.</p>
 <p>There is a type of input error, as I said, that might appear to be a bug. What
 actually is going on though is due to a technicality on how spaces are printed
-and the fact the program does not accept spaces other than a literal space<br />
+and the fact the program does not accept spaces other than a literal space
 <code></code>; when a character in the string to be found isn’t in the keyboard the
 program prints an error message and then exits (returning 1). But since the
 keyboard doesn’t have <code>'\n'</code> if you were to type a <code>'</code> and send a