Refactor k8s platform dependencies in docs #79
Description
We have a hard time duplicating all the special instructions for different k8s platforms dotted all over the docs. Bring them all together into one place to make it easier, as the number of platforms grows.
Remove all references to generic/AWS/GKE/AKS in the docs other than a single page for each and a table listing the platforms with links to the requirements/install/upgrade sections for each - then we refer to them by saying "Follow the install instructions for your platform", linking to the table.