message: update nav label
diff: @@ -5,7 +5,7 @@ nav:
  - Getting started: getting-started.md
  - Architecture: architecture.md
  - Packages: packages.md
  - - User guides:
  + - Platform User guides:
  - Glossary: user-guide-glossary.md
  - Onboarding and Registration: user-guide-reg-onboarding.md
  - Device Management: user-guide-device-management.md
  