Fix typo in Dep.Eff documentation.
Fix typo in Dep.Eff documentation.

kojiromike/Idris-dev,uuhan/Idris-dev,uuhan/Idris-dev,uuhan/Idris-dev,uuhan/Idris-dev,kojiromike/Idris-dev,kojiromike/Idris-dev,uuhan/Idris-dev,uuhan/Idris-dev,kojiromike/Idris-dev,uuhan/Idris-dev,kojiromike/Idris-dev,kojiromike/Idris-dev