Auto generate docs

Author: kdheepak

doc/panvimdoc.txt

@@ -115,7 +115,7 @@ The following are the metadata fields that the custom writer uses:
 
 - >project< (String) _required_: This is typically the plugin name. This is prefixed to all generated tags. (e.g. >*project-heading*<)
 - >vimversion< (String) _optional_: The version vim / neovim that the plugin is targeting. If not present, the version of vim in the available environment is used.
-- >toc< (Boolean) _optional_: Whether to generate table of contents or not.
+- >toc< (Boolean) _optional_: Whether to generate table of contents or not. If not present, this value is set to >true<.
 
 
 Example: