docs: add information about jquery-migrate

Author: trivikr

Diff for: docs/Templates.md

@@ -331,6 +331,7 @@ YARD's `fulldoc` template defines three javascript files:
     |   |   |   |-- app.js
     |   |   |   |-- full_list.js
     |   |   |   |-- jquery.js
+    |   |   |   |-- jquery-migrate.js
 
 The `app.js` is the primary javascript file for the HTML output.
 
@@ -339,6 +340,8 @@ search field menus (i.e. class list, method list, and file list).
 
 The `jquery.js` is copy of the jquery javascript library.
 
+The `jquery-migrate.js` is copy of the jquery migrate helper javascript library.
+
 ### Adding a Custom Stylesheet or Javascript
 
 To load additional stylesheets and javascripts with every page (except the search