♻️ [Concept] Refactor index page to include user-guide and runbook sections

[jasonBirchall]

👀 Purpose

• While working on platform documentation, I realised how awkward linking from the index page is. I believe this is partly because the index page does a fine job of describing the platform to someone who already knows what a platform is, but is terrible at guiding users through using our platform from scratch or even as a refresher.
• I hope the changes in this PR make linking more manageable and create a framework for good user engagement.
• I also hope that the team can start to publish some of its practices and ways of working.

♻️ What's changed

• The index page is heavily refactored and now includes two paths:
  -- A developer path: for a tenant using the platform, which comes under the guise of "user-guide"
  -- A platform engineer path: for the operators and engineers of the platform, intended for internal team use.

📝 Notes

• You can follow the instructions in the readme for a better look at the refactor, but I'll include screenshots below:

[AgaDufrat]

This sparks joy ✨ so neatly organised 🤩
I left a couple of minor comments.

[AgaDufrat]

Is there a reason for removing the intro section about Kubernetes? I think it was be quite informative, especially for less experienced devs. We have apprentices and juniors who would benefit from reading up on the technology before jumping into the user guide.

[jasonBirchall]

Indeed, it's helpful information, but it's not that helpful on the index page. Kubernetes scares people off at the best times, but throwing it into an introduction is unnecessary and distracts people away from what's important. I prefer to explain the abstraction (platform level) here, the what and why, and leave the technology choices to those who want to know about them. Technology choices (in my opinion) are far better placed in the "How the platform works" section.

[jasonBirchall]

Perhaps we could have a section in the "How the platform works" section explaining our technology decision-making.

[AgaDufrat]

Non-blocking or that important – I believe we don’t need to use absolute paths (which would save us some characters) but double check 🙈

Suggested change

	- [Gain access to a platform EKS Cluster](../../kubernetes/get-started/access-eks-cluster/index.html)
	- [Gain access to a platform EKS Cluster](/kubernetes/get-started/access-eks-cluster/index.html)

[jasonBirchall]

Absolutely, that's spot on. I have to use it for the local deployment to work, but I'll change it when it's moved to "Ready for Review".