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.

1990/jaw/README.md

@@ -64,8 +64,8 @@ directory it is run from.
 
 #### Minimal, Universal File Bundling (or, Functional Obfuscation in a Self-Decoding Unix Shell Archive)
 
-James A. Woods\
-Universities Space Research Association\
+James A. Woods<br>
+Universities Space Research Association<br>
 NASA Ames Research Center
 
 
@@ -108,16 +108,15 @@ within a modified Shannon model of communication, the 'shark' effort aims to
 construct a "shortest program" for source decoding in the Turing-universal Unix
 environment.
 
-----------------------------------------------
+```
+    Oh, the shark has pretty teeth, dear--
+    And he shows them pearly white
+    Just a jackknife has Macheath, dear--
+    And he keeps it out of sight.
 
->   Oh, the shark has pretty teeth, dear--\
->   And he shows them pearly white\
->   Just a jackknife has Macheath, dear--\
->   And he keeps it out of sight.\
-> \
->   -- Bertolt Brecht, Threepenny Opera
+    -- Bertolt Brecht, Threepenny Opera
+```
 
-----------------------------------------------
 
 ### Portability