Half-Life: Alyx update for 25 March 2020

Improved turning options in Preferences:

• Added "Continuous Turn", and associated turning speed options.
• Renamed "Quick turn" to "Snap Turn" to make its functionality clearer.
• Added option to disable controller turning.

Improved hand-over-mouth pose usability for Windows MR controllers.

Improved the resolution of impact decals on enemies.

Improved automatic detection of default Quality settings for some machine configurations.

Fixed an issue where some sounds didn't play as intended.

Fixed an issue where the main menu could become less responsive if you had many save games.

Fixed several crashes.