docs update - added InstallMode.ON_NEXT_SUSPEND option description (#928)

Author: disharmonized

docs/api-js.md

@@ -118,7 +118,7 @@ The `codePush` decorator accepts an "options" object that allows you to customiz
 
 * __mandatoryInstallMode__ *(codePush.InstallMode)* - Specifies when you would like to install updates which are marked as mandatory. Defaults to `codePush.InstallMode.IMMEDIATE`. Refer to the [`InstallMode`](#installmode) enum reference for a description of the available options and what they do.
 
-* __minimumBackgroundDuration__ *(Number)* - Specifies the minimum number of seconds that the app needs to have been in the background before restarting the app. This property only applies to updates which are installed using `InstallMode.ON_NEXT_RESUME`, and can be useful for getting your update in front of end users sooner, without being too obtrusive. Defaults to `0`, which has the effect of applying the update immediately after a resume, regardless how long it was in the background.
+* __minimumBackgroundDuration__ *(Number)* - Specifies the minimum number of seconds that the app needs to have been in the background before restarting the app. This property only applies to updates which are installed using `InstallMode.ON_NEXT_RESUME` or `InstallMode.ON_NEXT_SUSPEND`, and can be useful for getting your update in front of end users sooner, without being too obtrusive. Defaults to `0`, which has the effect of applying the update immediately after a resume or unless the app suspension is long enough to not matter, regardless how long it was in the background.
 
 * __updateDialog__ *(UpdateDialogOptions)* - An "options" object used to determine whether a confirmation dialog should be displayed to the end user when an update is available, and if so, what strings to use. Defaults to `null`, which has the effect of disabling the dialog completely. Setting this to any truthy value will enable the dialog with the default strings, and passing an object to this parameter allows enabling the dialog as well as overriding one or more of the default strings. Before enabling this option within an App Store-distributed app, please refer to [this note](https://github.com/Microsoft/react-native-code-push#user-content-apple-note).
 
@@ -539,6 +539,8 @@ This enum specifies when you would like an installed update to actually be appli
 
 * __codePush.InstallMode.ON_NEXT_RESUME__ *(2)* - Indicates that you want to install the update, but don't want to restart the app until the next time the end user resumes it from the background. This way, you don't disrupt their current session, but you can get the update in front of them sooner then having to wait for the next natural restart. This value is appropriate for silent installs that can be applied on resume in a non-invasive way.
 
+* __codePush.InstallMode.ON_NEXT_SUSPEND__ *(3)* - Indicates that you want to install the update _while_ it is in the background, but only after it has been in the background for `minimumBackgroundDuration` seconds (0 by default), so that user context isn't lost unless the app suspension is long enough to not matter.
+
 ##### CheckFrequency
 
 This enum specifies when you would like your app to sync with the server for updates, and can be passed to the `codePushify` decorator. It includes the following values: