Facebook confirmed Dark Mode for Messenger last October, and this past weekend, the company allowed some users to unlock the feature with a crescent moon(🌙) emoji. Now, the social media giant has officially announced the arrival of Dark Mode on its messaging app. Dark Mode on Messenger can be currently unlocked by sending the crescent moon emoji in a chat. After that, you can head over to the Settings menu to turn it on. However, Facebook has said that this a "limited-time only experience" so you may not be able to activate Dark Mode after some days with a moon emoji. Dark...