app config (startscript) macros/interfaces documentation

[joel-bluedata]

This is the big gap in our authoring docs at the moment.

As we tackle this we'll undoubtedly come across some rough spots and on a case-by-case basis we can decide whether to fix/improve them before documenting.

[kcsraju]

Now that configcli includes builtin command help, can this be considered done? If not, let's talk offline briefly.

[joel-bluedata]

It certainly helps a lot!

I think with a new configcli repo we have an opportunity to capture some stuff in the readme and/or wiki there.

[joel-bluedata]

@kcsraju will talk to you about this in email. Removing this from 0.5.0 milestone tho.