feat: add a new way of specifying which command(s) to run, and in what order

Currently, one has to do:

```
just-scripts build
```

to run *1* command. We can get rid of the need of lots of just.config.ts in monorepo packages if we an allow for multiple commands done:

```
just-scripts [transpile,copy-resources]
just-scripts [transpile,copy-resources]<>[asdf]
```

Or something similar