Reorganising the guide with respect to numbering

[guidodemmenie]

• Numbering sections
• organization of sections
• alignment with robotidy & robocop
  • should it be the other way around, lets discuss.

It would be nice if we have a numbering schema such that you can easily link back to rules, that can be used by tools or company or project specific style-guides to refer to the style-guide. The style-guide should be tool-agnostic, although the current tools will probably stay for a while, maybe some other tools come up in the future that implement the rules in the style-guide.