Documentation: add vmTools

[kip93]

Description of changes

#190809 states that there was no docs for runInLinuxVM, but when looking at the manual I found that the entire vmTools set is missing. I tried extracting the comments from that file into the docs, do some reformatting, and finally test and add some examples of my own.

Only thing missing are extractFs and extractMTDfs, for which I can't think of any clear / concise examples.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.11 Release Notes (or backporting 22.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[fricklerhandwerk]

@kip93 thanks for this great contribution, really well done. Sorry that you had to wait so much, I only now got to work off my backlog.

I left a few change requests concerning formatting, but in terms of content and wording this is exemplary. I like it a lot. We need more of that kind.

The structure of the attribute listings strikes me as a bit unusual, but we haven't converged on a consistent style across the manual anyway, so it's not really important.

[kip93]

Sorry for taking so long, this PR slipped my mind for the longest time.

I've rebased and updated to keep up to date with the changes in the source code, plus applied the suggested changes. The only standing issue is with the examples. Don't know how to improve them to make them more friendly to a new user, these seem to me clear for the topic at hand, and cover the more common scenarios that I can think of.

[fricklerhandwerk]

Looks awesome, thanks a lot for keeping at it!