Update _config.yml
Update _config.yml

Added instruction to make it a public calendar.
aerler/studyGroup,mbonsma/studyGroup,lwjohnst86/studyGroup,sjeblee/studyGroup,thesarahmeister/studyGroup,lwjohnst86/studyGroup,sjeblee/studyGroup,aerler/studyGroup,aerler/studyGroup,thesarahmeister/studyGroup,aerler/studyGroup,thesarahmeister/studyGroup,sjeblee/studyGroup,QuLogic/studyGroup,linamnt/studyGroup,mbonsma/studyGroup,lwjohnst86/studyGroup,linamnt/studyGroup,lwjohnst86/studyGroup,QuLogic/studyGroup,linamnt/studyGroup,mbonsma/studyGroup,aerler/studyGroup,mbonsma/studyGroup,mbonsma/studyGroup,QuLogic/studyGroup,linamnt/studyGroup,linamnt/studyGroup,aerler/studyGroup,QuLogic/studyGroup,thesarahmeister/studyGroup,lwjohnst86/studyGroup,mbonsma/studyGroup,sjeblee/studyGroup,sjeblee/studyGroup,thesarahmeister/studyGroup,thesarahmeister/studyGroup,sjeblee/studyGroup,aerler/studyGroup,thesarahmeister/studyGroup,lwjohnst86/studyGroup,linamnt/studyGroup,QuLogic/studyGroup,QuLogic/studyGroup