ETS2 - Sound Fixes Pack V21.6 (1.39.x)

Version 21.6 Changelog:
2 new rain interior sound variants, courtesy of Darkcaptain.
Interior sound volume for rain is now controlled by the interior sound volume slider.

Version 21.5:
Slight adjustments to rain interior sound volume.

Version 21.4:
Better variety of thunder sounds, courtesy of Darkcaptain.
Added feature to make thunder sounds more loud at night.
Close thunder may now play before/after thunder sounds that are further away.

Version 21.3:
Improved rain sound in the interior view.

Version 21.2:
Slight reduction in interior tire sound volume.

Authors: * SCS Software for base sounds
* Drive Safely for sound edits, some sound samples, and for compiling mod
* antonvezdehod for high speed tire sound
* Darkcaptain for a variety of thunder and rain sound samples
* Deltatristar500 for an external parking brake sound sample
* Grinch for default railroad crossing bell sound rework
* kriechbaum for light switch sound
* Vasily EVR for some air brake sound samples
* Zeemod for a wind sound sample