* fix(xunix): also mount shared object files with .so.N
* chore(Makefile): add test and test-integration targets
* chore(README.md): add hacking and troubleshooting sections
* chore(integration): fix tests under cgroupv2

Signed-off-by: Cian Johnston <cian@coder.com>
Co-authored-by: Dean Sheather <dean@deansheather.com>

…n os release (#127)

We had been mounting GPU libraries into the destination /usr/lib inside the inner container by default. This doesn't hold true for Redhat-based distributions, who use /usr/lib64 instead.

- Adds the capability to sniff /etc/os-release inside the inner container
- Modifies the destination path for bind-mounting GPU libraries to the inner container based on the detected OS release ID
- Adds integration testing for Envbox+NVidia GPUs (not run by default in CI)
- Attempts to automatically set CODER_USR_LIB_DIR if not specified.
- Adds the capability to manually set the inner mount path via CODER_INNER_USR_LIB_DIR.

* Mounts symlinks to auto-added GPU libs to inner container
* Tightens up gpuExtraRegex to avoid extraneous matches (e.g. libglib.so)
* Adds GPU integration tests to include regression test for redhat
* Adds GPU integration test with sample NVIDIA CUDA image

Adds missing docs regarding CODER_BOOTSTRAP_SCRIPT in README
Co-authored-by: Cian Johnston <cian@coder.com>