Improve visibility of Konnect migration documentation

## Definition of done
Rework the following page here and cross-link it to improve visibility.
https://developer.konghq.com/gateway/self-managed-migration/#how-do-i-migrate-to-konnect

## Information

From the discussions around the forums feedback the Konnect migration document is hidden and can be made more accessible. I have some ideas as suggestions to think through but I'm not adding them to the definition of done.

Size Small suggestions:
- Mention the migration page on the Konnect landing page, but also on the landing pages for all of the Konnect hosted CP options.
- Rename the migration doc to "From on-prem to Konnect"
- Remove the next-steps section. I think having the next-steps section at the bottom really makes it seem like "here are some vague instructions if its too hard call your representative".

Size M - L Suggestions

- This migrate [KGW configuration section ](https://developer.konghq.com/gateway/self-managed-migration/#migrating-data-planes) Could stand alone
- Create how-to's with simple examples for most of the sections in the existing doc, then create an on-prem -> Konnect migration Landing page, and index section that we can link users to.
- Build [this](https://developer.konghq.com/gateway/self-managed-migration/#migrating-data-planes) into a how-to
- Can we build the example workspace migration section into a how-to guide?

Basically, can we turn the individual pieces of this into docs. Right now this doc feels like a series of suggestions and light-examples. With the understanding that migration situations are usually unique, having copy-pasteable steps and easy-ish examples of the individual pieces could really help users establish what it is they are supposed to do before actually doing it.

## Due date (optional)

## Size

Rough estimate of effort:

- M (Medium)