Upload first official libgltf release: libgltf-0.0.0

News relative to previous draft version:
- Memory management improvements (fdo#81180)
- Reduced OpenGL requirements (version 3.3 -> version 3.0)
- Cleaned up API

Change-Id: Ie3caf8684a9f5e6a872a1ac35beafb94df03bcf5
Reviewed-on: https://gerrit.libreoffice.org/10744
Reviewed-by: Zolnai Tamás <zolnaitamas2000@gmail.com>
Tested-by: Zolnai Tamás <zolnaitamas2000@gmail.com>