bug(mac): forward and back buttons should be provided in help package help view

[sgschantz]

Describe the bug

In the Keyman Configuration app after viewing help text and clicking on a link, there should be an easy way to go back to the previous page by clicking a back button.

For example, install the Syriac/Aramaic keyboard and click on the link for Aramaic (Hebrew layout)

Keyman apps

• Keyman for Android
• Keyman for iPhone and iPad
• Keyman for Linux
• Keyman for macOS
• Keyman for Windows
• Keyman Developer
• KeymanWeb
• Other - give details at bottom of form

Keyman version

19 alpha