`zcmd.zig`: a `std.childProcess.run` replacement but with the ability of running `bash` pipeline

(originally posted here: https://zig.news/liyu1981/zcmdzig-a-stdchildprocessrun-replacement-but-with-the-ability-of-running-bash-pipeline-2k0h)

Continue reading `zcmd.zig`: a `std.childProcess.run` replacement but with the ability of running `bash` pipeline