So #791 added the core support for subprocesses, but at the last minute we had doubts about copying subprocess.run and decided to split out the high level convenience API into a separate PR: #791 (comment)

Some issues to consider (it's worth reading the whole discussion linked above):

• probably make check=True as the default. (Might be worth considering making the name more descriptive, so people would write allow_failure=True?)
• Passing stdout=PIPE to mean "capture the output" is pretty confusing (basically just dumping an implementation detail into the public API). Maybe capture_stdout=/capture_stderr= as boolean kwargs? Should we have capture= as a shorthand for setting both at once?
• If we're changing the default for check, we should change the name, because that's just enough of a change for people to trip over. trio.run_process is a good name.
• Should we do anything about the weird mess around shell=True and string-versus-list commands?