v6.0.0 - EFRCourier Release

Task Changes

1. There are now 4 instruction videos that explains each phase of the experiment
2. Externalized recall key presses are implemented in all recall phases
   • Externalized free recall for immediate free recall, final store recall, and final item recall
   • Required-response recall for cued recall
3. We can toggle open-loop stimulation during both encoding and recall phases

More details can be found here (https://upenn.app.box.com/folder/123854353822)