Update docs to clarify that an implicit collection can not have an index
Update docs to clarify that an implicit collection can not have an index

Signed-off-by: Matthew B White <dd513c8fd303aa277ae8aa28bfedef8a27ae8242@uk.ibm.com>

manish-sethi/fabric-sidedb,jimthematrix/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,jimthematrix/fabric,manish-sethi/fabric,manish-sethi/fabric-sidedb,hyperledger/fabric,hyperledger/fabric