added new banner options to the README.md
added new banner options to the README.md

BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK