More markdown {{ fixes

Changed 2013/hou/doc/example.markdown to avoud github wanrings of the form:

    The variable `{{` on line 38 in `2013/hou/doc/example.markdown` was not properly closed with `}}`. For more information, see https://docs.github.com/github/working-with-github-pages/troubleshooting-jekyll-build-errors-for-github-pages-sites#tag-not-properly-terminated.

2013/hou/doc/example.markdown

@@ -35,8 +35,8 @@ You can directly feed it to the renderer. If you're wondering about what the fol
 	ZnY|{|e
 	[mZ|\{\{#
 	[mZ|||f
-	kkdr{{%
+	kkdr\{\{%
-	lkdr{{>
+	lkdr\{\{>
 
 
 ## Basic structure