libjpeg-turbo 3.1.0 has been released - https://github.com/libjpeg-turbo/libjpeg-turbo/releases/tag/3.1.0

The change in header file locations is described in a beta release - https://github.com/libjpeg-turbo/libjpeg-turbo/releases/tag/3.0.90

The libjpeg-turbo source tree has been reorganized to make it easier to find the README files, license information, and build instructions. The documentation for the libjpeg API library and associated programs has been moved into the doc/ subdirectory, all C source code and headers have been moved into a new src/ subdirectory, and test scripts have been moved into a new test/ subdirectory.