update network readme.java.md (#10533)

Author: xseeseesee

specification/network/resource-manager/readme.java.md

@@ -26,6 +26,7 @@ directive:
 
 ``` yaml $(java) && $(multiapi)
 batch:
+  - tag: package-2020-06
   - tag: package-2020-05
   - tag: package-2020-04
   - tag: package-2020-03
@@ -37,6 +38,19 @@ batch:
   - tag: package-2019-02
 ```
 
+### Tag: package-2020-06 and java
+
+These settings apply only when `--tag=package-2020-06 --java` is specified on the command line.
+Please also specify `--azure-libraries-for-java-folder=<path to the root directory of your azure-sdk-for-java clone>`.
+
+``` yaml $(tag) == 'package-2020-06' && $(java) && $(multiapi)
+java:
+  namespace: com.microsoft.azure.management.network.v2020_06_01
+  output-folder: $(azure-libraries-for-java-folder)/sdk/network/mgmt-v2020_06_01
+  regenerate-manager: true
+  generate-interface: true
+```
+
 ### Tag: package-2020-05 and java
 
 These settings apply only when `--tag=package-2020-05 --java` is specified on the command line.