Option like --npm for Cargo projects

[jayvdb]

--npm is very nice. It is unfair that mprocs is better for JS projects than Rust projects ;-)

It would be nice to be able to use the existing list of binaries defined in Cargo.toml (s) , and be able to easily switch mprocs between running the debug or release versions.

Another benefit would be to perform a separate build phase of the binary (if it is missing?), so the mprocs UI can show "COMPILING" before it tries to run it and display "UP".