Enhance player stats; remove outdated methods

Removed various methods related to player and team statistics, game logs, and other functionalities from the README.md file. Added two new methods to the NhlStatisticsApi class: GetRealtimePlayerStatisticsBySeasonAndFilterExpressionAsync and GetTimeOnIcePlayerStatisticsBySeasonAndFilterExpressionAsync, providing detailed real-time player statistics and time on ice statistics for a specific player and season.