Windows batch processing: the usage of start

reference:

        http://blog.su61.com/2016/04/05/bat-start-ie-program/

to sum up:

        Using start will not block the execution of statements in the bat script, so you can open multiple different or the same programs in the bat script without getting stuck

        E.g:

                start C:\Programs\Unity\2017.4.26f1\Unity\Editor\Unity.exe -projectPath C:\Projects\TestProject, you can use the command line to directly open the unity project instead of a little bit every time