Enhance to comply with accessibility standards

[hunterlester]

https://github.com/electron/spectron#accessibility-testing
https://developer.mozilla.org/en-US/docs/Learn/Accessibility/HTML
https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA
https://reactjs.org/docs/accessibility.html

[hunterlester]

The browser should be able to be used 100% without a mouse, only with keyboard.

Navigate to https://www.nvaccess.org, download their open-source screen reader, and use with browser to reveal accessability shortcomings for visually impaired users.

[calumcraig]

The browser should be able to be used 100% without a mouse, only with keyboard.

• Can access the menus using ALT + eg F for file.
  • The shortcut letters for the relevant menus are only underlined when the user holds the ALT key. Do we want them to be underlined at all times (as they are in Firefox)?
    
• Have previously raised a minor issue around keyboard navigation which will be resolved once Electron is upgraded:
  Can't use keyboard arrow keys to navigate between browser menus #494
• Raised new issues:
  Can't use tab to navigate away from menu #525
  When using keyboard shortcut to open menu focus is on wherever mouse is hovering #526
  Right click keyboard button menu displayed under mouse pointer #527
  Keyboard shortcuts don't work while menu is open #528
• Can use TAB to navigate around the browser

Navigate to https://www.nvaccess.org, download their open-source screen reader, and use with browser to reveal accessibility shortcomings for visually impaired users.

• The reader says "not bookmarked button" and "is bookmarked button" for the bookmark button but simply "button" for all the other buttons:
  • Backward
  • Forward
  • Refresh
  • Hamburger
    not distinguishing between them. Do we want them to have unique identifiers?
• The reader doesn't say anything for the two brackets used in the keyboard shortcuts for forward / backward. Ctrl + ] / Ctrl + [ - it just reads "control plus" and "control plus".
• Reader seems to read onscreen text fine.

[hunterlester]

Moving this issue back to triage as an on-going effort.