import ScheduleLeagueV2 into __init__.py

Author: Maciej Kus

src/nba_api/stats/endpoints/__init__.py

@@ -242,6 +242,7 @@
 from .playerprofilev2 import PlayerProfileV2
 from .playervsplayer import PlayerVsPlayer
 from .playoffpicture import PlayoffPicture
+from .scheduleleaguev2 import ScheduleLeagueV2
 from .scoreboardv2 import ScoreboardV2
 from .shotchartdetail import ShotChartDetail
 from .shotchartleaguewide import ShotChartLeagueWide