blocking provides a thread pool
 for isolating blocking I/O in async programs.
 .
 Sometimes there's no way to avoid blocking I/O.
 Consider files or stdin,
 which have weak asyncronous support on modern operating systems.
 While IOCP, AIO, and io_uring are possible solutions,
 they're not always available or ideal.
 .
 Since blocking is not allowed inside futures,
 we must move blocking I/O onto a special thread pool
 provided by this crate.
 The pool dynamically spawns and stops threads
 depending on the current number of running I/O jobs.
 .
 This package contains the source
 for the Rust blocking crate,
 for use with cargo.