documentType data type doesn't match definition

After further discussion, we think that the Communication resource may be a better method for documenting the conveyance of educational material to the patient/guardian. We will remove Immunization.education and add content to the Boundaries and Relationships narrative indicating that Communication can be used to document the issuance of educational materials but that we welcome feedback on this approach. We will also indicate that the Communication resource could be a contained resource within the Immunization resource.