fixed code formatting issue in readme
fixed code formatting issue in readme

there was a missing triple-back-tick, causing fun formatting errors in code and documentation
joshrivers/wascally,LeanKit-Labs/wascally,dermidgen/wascally,derickbailey/wascally,BLaurent/wascally,UKHomeOffice/wascally,arobson/rabbot,arobson/wascally