Merge Product Compatibility Matrix into Docs

[lucasvaltl]

Description

• This PR merges the product compatibility matrix we have in notion into our documentation. The aim is for this new docs page to be the source of truth for what Gitpod can and cannot work with. In order to capture the responsible team, I added a small commented out table at the bottom that captures this info. This should be more readable.
• In addition, the required components page has been changed in its intent. It moved to the background section and is now aimed at giving an understanding of what dependencies Gitpod has and why. It does not include the version or type of dependencies that are supported - instead it refers to the product compatibility page for this.

Related Issue(s)

Fixes https://github.com/gitpod-io/gitpod/issues/10126

How to test

1. Review product compatibility page: Open netlify preview, navigate to docs>self-hosted>reference>product compatibility
2. Review changes to required components page: Open netlify preview, navigate to docs>self-hosted>background>dependencies

Release Notes

NONE

[csweichel]

Love it - this goes well and truly in the right direction. A few notes:

• on the product compatibility page, I'd use rowspan to group the categories. With a fixed stylesheet this makes it easier to read:
• reference architectures should IMHO become a point under Reference -> Architectures
• I'd move the "Background -> Dependencies" page under Reference

[lucasvaltl]

Discussing the process of how we want to align on changes to this matrix in the future in this internal RFC. Once we aligned on that, we will use what we aligned on to progress this PR :)

[nisarhassan12]

@lucasvaltl I'm closing this Please re-open it if it is still relevant. Thanks