toc change

Author: tshiya731

book/_toc.yml

@@ -125,6 +125,7 @@ parts:
     - file: End-of-course-survey.md
 
   - caption: In a Nutshell
+  - caption:  "Part 1: Python Standard Library "
     numbered: 2
     chapters:
     - file: basics/nutshell.md
@@ -158,6 +159,7 @@ parts:
       sections:
       - file: modules/nutshell/modules.ipynb
         title: Modules
+    - caption: "Part 2: Other Libraries"
     - file: numpy/nutshell.md
       title: Numpy
       sections: