add or enhance prefaces

[keichwa]

Marek says:

When we can do one thing multiple times, then I'd recommend adding a preface saying You can do X by using Y, Z, and Alpha. The reason for that is that a customer might see multiple ways to do something, but they might think that they need to do it multiple times.

Originally posted by @m-czernek in https://github.com/uyuni-project/uyuni-docs/pull/3556#discussion_r1925106207