minor modification to Docker.md
minor modification to Docker.md

NCBI-Hackathons/Cancer_Epitopes_CSHL,NCBI-Hackathons/Cancer_Epitopes_CSHL,NCBI-Hackathons/Cancer_Epitopes_CSHL,NCBI-Hackathons/Cancer_Epitopes_CSHL,NCBI-Hackathons/Cancer_Epitopes_CSHL