Adding rollout disclaimer

Author: lostintangent

cli/README.md

@@ -327,6 +327,8 @@ If you never release an update that is marked as mandatory, then the above behav
 
 #### Rollout parameter
 
+**IMPORTANT: In order for this parameter to actually take affect, your end users need to be running version `1.6.0-beta+` (for Cordova) or `1.8.0-beta+` (for React Native) of the CodePush plugin. If you release an update that specifies a rollout property, no end user running an older version of the Cordova or React Native plugins will be eligible for the update. Therefore, until you have adopted the neccessary version of the CodePush SDK, we would advise not setting a rollout value on your releases, since no one would end up receiving it.**
+
 This specifies the percentage of users (as an integer between `1` and `100`) that should be eligible to receive this update. It can be helpful if you want to "flight" new releases with a portion of your audience (e.g. 25%), and get feedback and/or watch for exceptions/crashes, before making it broadly available for everyone. If this parameter isn't set, it is treated equivalently to `100`, and therefore, you only need to set it if you want to actually limit how many users will receive it.
 
  When leveraging the rollout capability, there are a few additional considerations to keep in mind:
@@ -570,4 +572,4 @@ You can clear the release history associated with a deployment using the followi
 code-push deployment clear <appName> <deploymentName>
 ```
 
-After running this command, client devices configured to receive updates using its associated deployment key will no longer receive the updates that have been cleared. This command is irreversible, and therefore should not be used in a production deployment.
+After running this command, client devices configured to receive updates using its associated deployment key will no longer receive the updates that have been cleared. This command is irreversible, and therefore should not be used in a production deployment.