The package set is not maintained. It is also not used by most of the
BEAM community. Removing it to allow a more useful set of tools fit to
the BEAM community in Nixpkgs.
The documentation got a bit stale compared to actual contents of
nixpkgs. This commit focuses on updating existing docs, not on making
sure all details of beam packages are covered.
This allows you to turn on debug infor for all the beam packages in the
system with a single change at the top level. This is required for
debugging and dialyzer work. It also allows you to switch it on on a
package by package basis.