Change authors field to author in config

Author: SandraVerhagen

book/_config.yml

@@ -1,5 +1,5 @@
 title: Introduction to Python
-authors: Exploring the Grand Challenges & the TeachBooks Teams from Delft University of Technology, built with <a href="https://teachbooks.tudelft.nl/">TeachBooks</a> and <a href="https://jupyterbook.org/">Jupyter Book</a>, <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="license noopener noreferrer"">CC BY 4.0<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/cc.svg" alt=""><img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/by.svg" alt=""></a> #add your own name here
+author: Exploring the Grand Challenges & the TeachBooks Teams from Delft University of Technology, built with <a href="https://teachbooks.tudelft.nl/">TeachBooks</a> and <a href="https://jupyterbook.org/">Jupyter Book</a>, <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="license noopener noreferrer"">CC BY 4.0<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/cc.svg" alt=""><img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/by.svg" alt=""></a> #add your own name here
 logo: figures/TUDelft_logo_rgb.png #add your own logo here
 
 execute: