.arcconfig
Print instructions for `meteor run ios-device`.

Summary: Task: https://app.asana.com/0/15750483766338/16682276437409

Test Plan:
Run `meteor run ios-device` with and without Xcode already open, with and
without a device connected.

Reviewers: sashko, avital, nim, slava

Reviewed By: sashko

Differential Revision: https://phabricator.meteor.com/D855
Print instructions for `meteor run android-device`.

Summary: Task: https://app.asana.com/0/15750483766338/16682276437409

Test Plan:
Run `meteor run android-device` with and without an Android device
connected.

Reviewers: sashko, avital, nim, slava

Differential Revision: https://phabricator.meteor.com/D856