Update concepts.adoc
Update concepts.adoc

fixed typos
DevCamp4Kids/materials,eloudsa/materials,eloudsa/materials,devoxx4kids/materials,devoxx4kids/materials,ooms/materials,ooms/materials,ooms/materials,ooms/materials,wadael/materials,cristinanegrean/materials,ooms/materials,henkjurriens/materials,eloudsa/materials,cristinanegrean/materials,devoxx4kids/materials,devoxx4kids/materials,DevCamp4Kids/materials,cristinanegrean/materials,DevCamp4Kids/materials,vorburger/materials,devoxx4kids/materials,henkjurriens/materials,vorburger/materials,wadael/materials,vorburger/materials,DevCamp4Kids/materials,wadael/materials,wadael/materials,devoxx4kids/materials,vorburger/materials,devoxx4kids/materials,henkjurriens/materials,henkjurriens/materials,ooms/materials,cristinanegrean/materials,ooms/materials