Update Root README (#9327)
Update Root README (#9327)

* Update root README for the March 2020 release

* Additional changes for March release and general cleanup
selvasingh/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java,selvasingh/azure-sdk-for-java,selvasingh/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java,Azure/azure-sdk-for-java