Available Skaffold docker images - add more detail

Expected behavior

As user, I want to find more information about the available Skaffold docker images in skaffold.dev web page: what they have, tools included, when are those updated, etc.

Actual behavior

Right now, the only information we have related to the available docker images is under https://skaffold.dev/docs/install/#standalone-binary.

Information

We can add more information about the images created in the different moments of our CI/CD process:

• Tools included in the images, e.g, gcloud, docker, kpt, etc
• When are the images created: lts images vs latest vs edge
• Tagging strategies used when are created
• etc

We'll need to check if we want to add that information in the same https://skaffold.dev/docs/install/#standalone-binary section, or add a new one.