don't remove self from example code in the HTML output (closes #13223)

Patch by Víctor Terrón.
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index 160ad4a..254fe40 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -581,10 +581,15 @@
             elif pep:
                 url = 'http://www.python.org/dev/peps/pep-%04d/' % int(pep)
                 results.append('<a href="%s">%s</a>' % (url, escape(all)))
+            elif selfdot:
+                # Create a link for methods like 'self.method(...)'
+                # and use <strong> for attributes like 'self.attr'
+                if text[end:end+1] == '(':
+                    results.append('self.' + self.namelink(name, methods))
+                else:
+                    results.append('self.<strong>%s</strong>' % name)
             elif text[end:end+1] == '(':
                 results.append(self.namelink(name, methods, funcs, classes))
-            elif selfdot:
-                results.append('self.<strong>%s</strong>' % name)
             else:
                 results.append(self.namelink(name, classes))
             here = end