Link to issue number:

Fixes #15257

Summary of the issue:

For an installed add-on the add-on store displays the help button, even if no help is available.

Description of user facing changes

Hide the help button if no help is available

Description of development approach

Fix typing and explicitly check if a help doc is available when determining if to display the help button

Testing strategy:

Test with the add-ons and STR in #15257

Known issues with pull request:

If there's no help available for the selected NVDA language or english, the help button will not be shown.
NVDA will not fallback to available languages or than english.

Change log entries:

N/A

Code Review Checklist:

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