Split script from arguments in run command

before 
```bash
./bin/melody help run
Usage:
 run [--no-cache] [--prefer-source] [script1] ... [scriptN]

Arguments:
 script                Which script do you want to run?
```

after
```bash
./bin/melody help run
Usage:
 run [--no-cache] [--prefer-source] script [arguments1] ... [argumentsN]

Arguments:
 script                Which script do you want to run?
 arguments             Which arguments do you want to pass to the script?
```