Accessibility requirements
Spoke to @bgtlover in #accessibility:gnome.org on Matrix:
- The screen reader must turn on if the user presses Alt+Super+S
- If the user doesn't leave the first page, we should announce using speech-dispatcher or similar: "Screen reader can be turned on with the keyboard shorcut Alt + Super + s"
- Do we usually show Alt+Super+S or Super+Alt+S? Check the shortcuts window
Prior art: https://github.com/elementary/installer/blob/master/src/MainWindow.vala#L104