Update TOC to include getting_started lecture

Author: Zahra-khanzadeh

lectures/_toc.yml

@@ -5,7 +5,7 @@ parts:
   numbered: true
   chapters:
   - file: about_py
-  # - file: getting_started
+  - file: Getting_started
   # - file: python_by_example
   # - file: functions
   # - file: python_essentials