Close to tray is coming the Betterbird 153

The Thunderbird folks integrated the add-on Close to tray while at the same time dropping the minimise to tray function.

We restored the latter. The article screenshot shows the relevant UI in the settings. And of course it works on Linux, too, where as Thunderbird users have been waiting since 2020, and now, the Windows version doesn't even support minimise to tray any more.

These are the relevant preferences:

• mail.minimizeToTray
• mail.closeToTray
• mail.startupMinimized (in Thunderbird: mail.closeToTray.startInTray)