Remove utilities docs

Author: ajalt

docs/utilities.md

@@ -141,10 +141,6 @@ nav:
       - 'Testing Your Commands': testing.md
       - 'Testing Environment Variables': testing/#testing-environment-variables
       - 'Custom Testing': testing/#custom-testing
-  - 'Utilities':
-      - 'Launching Editors': utilities.md
-      - 'Input Prompts': utilities/#input-prompts
-      - 'Confirmation Prompts': utilities/#confirmation-prompts
   - 'Shell Completion':
       - 'Supported Functionality': autocomplete.md
       - 'Enabling Completion': autocomplete/#enabling-completion