cloud-docs rst->md conversion

[matkuliak]

What's Inside

Significant changes.

Preview

https://crate-cloud--55.org.readthedocs.build/en/55/

Highlights

• howtos - rst->md

  • reworked index to use the grid layout, added cards
  • deleted howtos/connect-to-cluster/index.md and placed the card within it directly into index.md
  • added a reference point to tutorials/quickstart

• tutorials/edge

  • converted rst->md
  • reworked index, added the cards similar to others

• reference - rst->md

  • removed subscription-plans.md as it's superseded by services

• tutorials/deploy/croud.md - rst->md

  • added a card to cannonical croud docs to make them more prominent

Checklist

• Link to issue this PR refers to (if applicable): https://github.com/crate/tech-writing/issues/402
• CLA is signed

[matkuliak]

Went through all the changes pretty rigorously multiple times, but it's a big change so would appreciate a review from anyone interested. Thank you in advance.

The main concern is broken links/references, although checks should catch those. Technically everything should work, quite sure of that.

[proddata]

Suggested change

	## Cluster Management
	:::
	## Cluster Management
	:::

[proddata]

wrapping them doesn't show them in the toc

[amotl]

Hi. That's a huge amount of work which went into this patch, thank you very much! 💯

Currently, I don't have the capacity to review it completely, roughly about 4,000 lines being changed, so please either wait for another cycle (one day or two), or just merge when you need it, and when there are no other objections. I've just added a few suggestions while quickly navigating into the patch, nothing serious.

[amotl]

Maybe it also works like this to refer to a doc label? I didn't try, yet. If it works, it would also be a good candidate to expand the authoring guide about referencing correspondingly.

Suggested change

	[here](https://crate.io/docs/cloud/cli/en/latest/commands/clusters.html).
	[here](inv:croud#commands/clusters).

[amotl]

Also added a note about this where to improve the authoring guidelines.

-- crate/crate-docs-theme#472 (comment)

[matkuliak]

Hi @amotl. Do you still need couple more days to look this over, or are you happy with it?
I've got some feature docs in-progress and would like to merge this first and do them in Markdown already. Not to rush you, of course. Thanks!

[amotl]

Hi Matej. I can't find the cycles, unfortunately. I think it will be good to go, please go ahead. Thanks again!