Update readme for Synapse management SDK May release (#14054)
Update readme for Synapse management SDK May release (#14054)

* Update readme for Synapse management SDK May release

* Add package-2021-05-preview

* Address comment

Co-authored-by: Dongwei Wang <299bd875950c3f8e46c49d604050d0d2e57edd90@microsoft.com>
naveedaz/azure-rest-api-specs,solankisamir/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,johanste/azure-rest-api-specs,naveedaz/azure-rest-api-specs,johanste/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,solankisamir/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs