Update ReadMe.md
Update ReadMe.md

- Added Destination to log sink create.
- Add missing `\` to the gcloud function deploy.
- Add LOG_EXPORT_NAME var
GoogleCloudPlatform/professional-services,GoogleCloudPlatform/professional-services,GoogleCloudPlatform/professional-services,CloudVLab/professional-services,CloudVLab/professional-services,CloudVLab/professional-services,CloudVLab/professional-services,CloudVLab/professional-services,GoogleCloudPlatform/professional-services,GoogleCloudPlatform/professional-services,GoogleCloudPlatform/professional-services,CloudVLab/professional-services,GoogleCloudPlatform/professional-services,GoogleCloudPlatform/professional-services,CloudVLab/professional-services,GoogleCloudPlatform/professional-services