Auto generate docs

Author: kdheepak

doc/panvimdoc.txt

@@ -320,7 +320,8 @@ Notice that both headings and subheadings have tags.
 SUB HEADING 3 ~
 
 Sub headings are upper cased, but do not have tags. They are also not included
-in the TOC.
+in the TOC. They are suffixed with `~` which highlights as **bold** text when
+the file is viewed on GitHub.
 
 MARKDOWN LINKS                                      *panvimdoc-markdown-links*