Create firmware update instructions

en/firmwareupdate.md/en/firmwareupdate.md

+# Currently: Broccoli (day 1 - 19:00)
+https://card10.badge.events.ccc.de/release/card10-v1.2.zip
+
+# Update the firmware release on your card10
+* download the current firmware `.zip` file to your computer
+* extract it
+* put your card10 into [USB storage mode](/en/gettingstarted#usb-storage)
+* copy over the files you just extracted directly into the main folder
+* eject your device (if you're doing this in the command line: don't forget the `sync` on linux)
+* switch your card10 on and off again
+
+# Previous Releases
+
+## Asparagus
+As of Day 1, 18:00
+Asparagus is the firmware that is loaded on the card10s handed out on day 1 from 18:00
+There are currently no previous releases
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