Release v2.2.3

Patch/v2.2.3 (#69)

* VMT context menu: Fix VTF generation

* VMF: Fix displacements processing

* Bump: v2.2.2

* VTF: Add conversion to SRGB

* FGD Generator: Fix markers handling

* Update readme.md

* Fix duplicate sentence in legality section

Removed duplicate sentence about contacting Valve for commercial use of the Source Engine SDK.

* VMF: Fix displacement vertex generation for precised vertex data