Update README.rst
Update README.rst

Remove explicit list of version from the front page (simplify release). Update some text.
rjschwei/azure-sdk-for-python,lmazuel/azure-sdk-for-python,SUSE/azure-sdk-for-python,Azure/azure-sdk-for-python,AutorestCI/azure-sdk-for-python,Azure/azure-sdk-for-python,v-iam/azure-sdk-for-python,Azure/azure-sdk-for-python,Azure/azure-sdk-for-python