"put your code here" proposal

[accetto]

I want to propose to add a hint where to put the user's own script code.
I think it would be helpful, especially for new users.

Currently the generated code ends like this:

### END OF CODE GENERATED BY Argbash (sortof) ### ])
# [ <-- needed because of Argbash
# ] <-- needed because of Argbash

So it could be something like this:

### END OF CODE GENERATED BY Argbash (sortof) ### ])
# [ <-- needed because of Argbash
### PUT YOUR OWN SCRIPT CODE HERE
# ] <-- needed because of Argbash