[ReleasePR operationalinsights] OperationalInsights - update readme files for cli extension update (#1591)

Create to sync Azure/azure-rest-api-specs#13999
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/master...AzureSDKAutomation:sdkAuto/operationalinsights?expand=1)

Author: msftbot[bot]