add api-version for templatespecs (Azure#12197)

Author: ArcturusZhang

specification/resources/resource-manager/readme.go.md

@@ -22,6 +22,7 @@ go:
 
 ``` yaml $(go) && $(multiapi)
 batch:
+  - tag: package-templatespecs-2019-06-preview
   - tag: package-features-2015-12
   - tag: package-locks-2016-09
   - tag: package-locks-2015-01
@@ -61,6 +62,16 @@ batch:
   - tag: package-resources-2019-07
 ```
 
+### Tag: package-templatespecs-2019-06-preview and go
+
+These settings apply only when `--tag=package-templatespecs-2019-06-preview --go` is specified on the command line.
+Please also specify `--go-sdk-folder=<path to the root directory of your azure-sdk-for-go clone>`.
+
+``` yaml $(tag) == 'package-templatespecs-2019-06-preview' && $(go)
+namespace: templatespecs
+output-folder: $(go-sdk-folder)/services/preview/resources/mgmt/2019-06-01-preview/$(namespace)
+```
+
 ### Tag: package-resources-2019-07 and go
 
 These settings apply only when `--tag=package-resources-2019-07 --go` is specified on the command line.