Update _config.yml

_config.yml

@@ -43,7 +43,7 @@ aux_links:
 footer_content: "Copyright &copy; 2017-2019 Patrick Marsceill. Distributed by an <a href=\"https://github.com/pmarsceill/just-the-docs/tree/master/LICENSE.txt\">MIT license.</a>"
 
 # Footer last edited timestamp
-last_edit_timestamp: true # show or hide edit time - page must have `last_modified` defined in the frontmatter
+last_edit_timestamp: true # show or hide edit time - page must have `last_modified_date` defined in the frontmatter
 last_edit_time_format: "%b %e %Y at %I:%M %p" # uses ruby's time format: https://ruby-doc.org/stdlib-2.7.0/libdoc/time/rdoc/Time.html
 
 # Footer "Edit this page on GitHub" link text