CB-7970 Add cordova-plugin-vibration support for Windows Phone 8.1

Added Windows Phone 8.1 support
Updated documentation

[JIRA issue](https://issues.apache.org/jira/browse/CB-7970)

[This change](https://github.com/MSOpenTech/cordova-plugin-vibration/compare/CB-7970?expand=1#diff-5db2c860d4e7e5ef74eb7cfc33d99f8eR86) is because `wp` platform does not support `vibrateWithPattern` actually