add mission date of 2.2 release (#1160)

* update to next version number

* fixed date for 2.2 release

* go back for commit to master

README.md

@@ -14,7 +14,7 @@ A contactless jukebox for the Raspberry Pi, playing audio files, playlists, podc
 
 * **Gitter Community** we got ourselves a gitter community; chat us up at https://gitter.im/phoniebox
 
-* **Phoniebox [2.2](https://github.com/MiczFlor/RPi-Jukebox-RFID/milestone/4?closed=1) released (2020-xx-xx)**
+* **Phoniebox [2.2](https://github.com/MiczFlor/RPi-Jukebox-RFID/milestone/4?closed=1) released (2020-11-23)**
 
 The [2.2](https://github.com/MiczFlor/RPi-Jukebox-RFID/milestone/4?closed=1) release was pushed through the doors with many contributors (some of which in alphabetical order): @andreasbrett @BerniPi @juhrmann @Luegengladiator @MarkusProchaska @MarlonKrug @patrickweigelt @princemaxwell @RalfAlbers @s-martin @themorlan @veloxidSchweiz @xn--nding-jua. [List of all contributors](https://github.com/MiczFlor/RPi-Jukebox-RFID/graphs/contributors)