Added extra config steps for running IOCs on macOS

[hyperrealist]

Adds instructions to circumvent issue #128

[mrakitin]

Thanks for the contribution, @hyperrealist! I'll try to run it locally later, just wanted to add a couple of notes:

• I like the grep -o option, very useful to extract the matching substring only.
• xargs seems very useful for formatting the inputs and arranging output in columns :)
• a great solution to add multiple aliases to the loopback interface. I think we can also suggest cleaning up them with -alias if people want to clean the configuration after running the tutorial.

[hyperrealist]

I think adding an optional cleanup step is a neat idea. I added a commit to the PR.

[mrakitin]

Good additions, @hyperrealist! I think it will also be very beneficial to users to have these commands in a shell script so that they can be executed easier. But it's an optional suggestion.

[hyperrealist]

@mrakitin, I think a better approach might be to wrap start_supervisor.sh around functionality that does the loopback interface configuration automatically if it is invoked on a macOS system. That way, there will be no extra steps for macOS users. What do you think about that?

[mrakitin]

Good idea, let's try.