add author and link information

lectures/_config.yml

@@ -1,5 +1,5 @@
 title: Python Programming for Economics and Finance
-author: Thomas J. Sargent & John Stachurski
+author: Thomas J. Sargent and John Stachurski
 logo: _static/qe-logo.png
 description: This website presents a set of lectures on python programming for economics, designed and written by Thomas J. Sargent and John Stachurski.
 
@@ -27,6 +27,11 @@ sphinx:
     html_theme: quantecon_book_theme
     html_static_path: ['_static']
     html_theme_options:
+      authors:  
+        - name: Thomas J. Sargent
+          url: http://www.tomsargent.com/
+        - name: John Stachurski
+          url: https://johnstachurski.net/
       dark_logo: quantecon-logo-transparent.png
       header_organisation_url: https://quantecon.org
       header_organisation: QuantEcon