Add Detailed Information for game_id Parameter in parameters.md

[gmortensen]

This pull request adds detailed information for the game_id parameter in the parameters.md file. The game_id parameter is frequently used throughout the nba_api library, but it previously lacked detailed documentation. The following updates have been made:

Pattern for game_id:

• Added regex pattern ^\d{10}$ to validate the format of game_id.

Explained the significance of the third digit in the game_id, which functions as a flag indicating the type of season:
1: Preseason game
2: Regular season game
3: All-Star weekend game
4: Playoff game
5: Play-in game

Included examples to illustrate the format and the significance of the third digit:

• 0022200147: Regular season game
  

• 0012200147: Preseason game
  

Version:
This update is for version 1.5.0.

Please let me know if there are any additional changes or improvements needed for this documentation update.

Thank you for your time and consideration in reviewing this PR.

[rsforbes]

@gmortensen - Apologies for not getting to this sooner.

The parameters.md file is auto-generated via generator.py. The generator then looks to mapping.py. If you're able to incorporate your changes there, I think you'll be set to go.