instructions for es multinode + kib external access

[shainaraskas]

Harvested all of the content from the old install stack tutorial that was missing from the other docs.

namely:

1. set up your first node so other nodes can connect to it (example in RPM, Win - the steps have a different order across install types because of the availability of the elasticsearch-reconfigure-node tool for RPM and debian)
2. expose kibana so remote users can connect (example)

^ both of these were added as optional steps to the es and kibana install tutorials. I also simplified and deduplicated initial TCP config info across the install guides

Wonder if the kibana instructions should instead be part of the config step, but not sure if the correct server.host value needs to be present when kibana is enrolled. this preserves the order from the old tutorial (config then start).

I also rounded up the ports from the old image and added them in the installation overviews - not necessarily the best spot but maybe an adequate one? took the content from a knowledge article and added the relevant settings

open to feedback about whether this is a good addition or not

closes https://github.com/elastic/docs-projects/issues/462

[eedugon]

I think I forgot to apply my review comments last week before your day started and I started to run tests in my afternoon :)

Sharing them now, as I think they are still relevant. Please ignore otherwise.

I'll start a new review now checking the changes we talked about the procedure itself.

[eedugon]

Looks really great. I've left a few comments for your consideration.
If you need another review let me know!