clarify behaviour of updateDialog

Author: geof90

README.md

@@ -192,7 +192,7 @@ The method accepts an options object that allows you to customize numerous aspec
 * __ignoreFailedUpdates__ (Boolean) - Indicates whether you would like to automatically ignored updates which are available, but have been previously attemped to install, but failed. Defaults to `true`.
 * __installMode__ (CodePush.InstallMode) - Indicates whether you would like to restart the app immediately after the update has been installed, or wait until the next app resume or restart. Defaults to `CodePush.InstallMode.ON_NEXT_RESTART`
 * __rollbackTimeout__ (Number) - The number of seconds that you want the runtime to wait after an update has been installed before considering it failed and rolling it back. Defaults to `0`, which disables rollback protection.
-* __updateDialog__ (UpdateDialogOptions) - The options object used to customize the dialog displayed to the user. Defaults to `null`. A falsey value will disable the display of a dialog, in which case updates will be downloaded automatically. The list of `UpdateDialogOptions` are as follows:
+* __updateDialog__ (UpdateDialogOptions) - The options object used to customize the dialog displayed to the user. Unspecified fields in the object provided will default to the values shown below, hence the boolean flag `true`, or any other truthy value will cause the default values below to be used. A falsey value will disable the display of a dialog, in which case updates will be downloaded automatically. Defaults to `null` (do not show a dialog). The list of `UpdateDialogOptions` are as follows:
     * __appendReleaseDescription__ (Boolean) - Indicates whether you would like to append the description of an available release to the notification message which is displayed to the end-user. Defaults to `false`.
     * __descriptionPrefix__ (String) - Indicates the string you would like to prefix the release description with, if any, when displaying the update notification to the end-user. Defaults to `" Description: "`
     * __mandatoryContinueButtonLabel__ (String) - The text to use for the button the end-user must press in order to install a mandatory update. Defaults to `"Continue"`.