refactor centos to opensuse migration (#485)

[Hooverdan96]

Continuation of PR #507 Fixes #485

This pull request's proposal

• rename file (commit bd05b9f78e635070bafe1dfd44644e9b41481c54)
• move to more generic CentOS to openSUSE description (commit ac1e2451dee64cb99acf8f41a0503b631ec44f00)
  • refactor text to remove v4 references, where applicable, and refer more to openSUSE versions.
  • semantic line break updates
  • replaced you/us/we with other terms/constructs.
• update toctree, file references and add entry to redirect.txt file (commit 012711fd1179ffd404bcdd27c2dc91e3327a57e7)

Checklist

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

[Hooverdan96]

@phillxnet Thanks for proof-reading once more.

[phillxnet]

PR product PRODUCTION published.

Just a minor note here, we do contextually acknowledge our use of "openSUSE versions" are referencing our "Built on openSUSE" and the "OpenSUSE Installer" is followed directly with a reference to our "Rockstor's "Built on openSUSE". But we may want to re-visit this doc and make more 'marks aware' our use of the "openSUSE" mark re the terms we acknowledge in our installer docs.

We should always take care to not claim we are openSUSE is my point. But we do that very clearly everywhere else. But I think this new doc version is cutting it a little close re the explicity title use of the "openSUSE" mark.

See: https://rockstor.com/eula.html (Our EULA) which in turn links to:

https://en.opensuse.org/openSUSE:Trademark_guidelines

I'll present a PR to amend our use, in sub-titles at least, of what I'd not realised in the review is a little too close for comfort re marks as outlined in the above.