Fix item 16 of guiding principles

[SaschaCowley]

Link to issue number:

None

Summary of the issue:

Item 16 of the Guiding Principles in our Product Vision does not render correctly.

Description of user facing changes:

The item, and its child items, render correctly.

Description of developer facing changes:

None

Description of development approach:

Removed erroneous single-space indent before item 16 in projectDocs/product_vision.md.

Testing strategy:

Previewed the markdown before committing.

Known issues with pull request:

None

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

@coderabbitai summary