OLMIS-1654: Added first draft of message grammar guidelines
OLMIS-1654: Added first draft of message grammar guidelines

OpenLMIS/openlmis-requisition-ui,OpenLMIS/openlmis-requisition-refUI,OpenLMIS/openlmis-requisition-ui,OpenLMIS/openlmis-requisition-refUI,OpenLMIS/openlmis-requisition-refUI,OpenLMIS/openlmis-requisition-ui,OpenLMIS/openlmis-ui-components,OpenLMIS/openlmis-ui-components,OpenLMIS/openlmis-ui-components