add nginx/haproxy connect example documentation

[eikenb]

includes helper script to extract config files and run command in screen
session.

[eikenb]

Thanks for all the suggestions @kaitlincarter-hc! Super helpful and nice of you.

I've made all the suggested text changes except regarding the script/config-files. Regard them, I went back and forth on having the config files already in the repo vs. having them generated by the script. There are a couple(ish) options.

1. Have a sub-directory with the all the config files and templates (the things the script generates from the doc) already in place and use the script to keep it in sync with the doc (update the doc then extract the files to test/save).

2. Only have the script and let the users generate the files themselves for testing.

I went with the 2 as it kept things cleaner and I figured if the person was technical enough to run the tests, they could figure out how to use the script.

Switching to 1 would, I think, make it easier to run the tests at the expense of cluttering things up a bit. I would split the script into 2 parts if I did that. One to extract the config and template files and one to actually run the tests (which would also simplify it a bit).

Do you think 1 would be better?

Thanks again.

[kaitlincart]

I think for the repo, option 2 is probably better. For the Learn guide I'll simplify things a little!

[eikenb]

Made a few tweaks and included the haproxy doc (which was based on nginx one and nearly identical... so I figured it has already been reviewed).