Rewrites the NIF bindings, the Elixir that calls them, and docs/coverage.md
from the MuJoCo headers this build is against.
$ mix ex_mujoco.gen
$ mix ex_mujoco.gen --check
The headers come from the MuJoCo that scripts/prepare_mujoco.exs prepared, so
the bindings and the library are always the same version. What is bound is
c_src/manifest.exs; everything else the headers describe is written to
docs/coverage.md as unbound, with the reason.
--check writes nothing and exits non-zero when a generated file disagrees with
what would be generated. CI runs it on every push, so a hand-edited generated
file, or a MuJoCo version bump without a regeneration, fails the build rather
than drifting.
The output is committed: a package that generated its bindings at build time would need a generator on the machine that builds it, and would make two builds of the same version differ.