Document rocknets creation and use.

[FroggyFlox]

Fixes #256
@phillxnet, ready for review.

This pull request's proposal

Following the merging of rockstor/rockstor-core#2207, we should add corresponding documentation on rocknets. This pull request (PR) thus adds the following to Rockstor's documentation:

• description of the "docker" type when creating a new network connection.
• description of the new "Networking" dialog window and its use to edit ports' publication state as well as creating/joining/leaving rocknets

@phillxnet, note that I created and placed all new screenshots related to the rock-ons documentation in a new folder inside the images directory in the root folder... It was in an effort to limit the multiplication of screenshots in the docker-based-rock-ons folder; I was thinking of progressively moving all images for the docker-based-rock-ons folder in future PRs. Let me know if you think that's an appropriate organization.

Checklist

• With the proposed changes no Sphinx errors or warnings are generated.
• I have added my name to the AUTHORS file, if required (descending alphabetical order).

[phillxnet]

@FroggyFlox Re:

Let me know if you think that's an appropriate organization.

That makes sense. Your call as you see fit really. As long the the result renders OK it would be good to do what ever tidy/organisation we can manage.
Thanks for looking after this, much appreciated, and thanks also for your efforts in not only adding this new feature but also tending to the docs.
I can hopefully take a look soon but if your're find with what you have submitted here then I am also.

[FroggyFlox]

I can hopefully take a look soon but if your're find with what you have submitted here then I am also.

No worries... It would only be useful once the next rpm is released anyway so I don't see an emergency to rush this PR for now.

Thanks a lot for your time, and take care!

[FroggyFlox]

@phillxnet , I've updated the images' :scale: parameter to use :width: 100% for those that could benefit from it, as discussed in #258. This was done only in the files changed in this PR, however:

• overview.rst
• network.rst

It still builds fine on my end so based on your previous comment, I might merge this in and publish it in a little bit given the feature is now released in Rockstor 4.0.5.

Cheers!