Improved documentation of Analytics initializer
Improved documentation of Analytics initializer

ibm-bluemix-mobile-services/bms-clientsdk-swift-analytics,ibm-bluemix-mobile-services/bms-clientsdk-swift-analytics,ibm-bluemix-mobile-services/bms-clientsdk-swift-analytics,ibm-bluemix-mobile-services/bms-clientsdk-swift-analytics,ibm-bluemix-mobile-services/bms-clientsdk-swift-analytics