Docs survey feedback: Remove or add context to hosts: all in examples

[samccann]

Some of our examples use hosts: all in playbooks. This could be dangerous, since most playbooks are design to run only on certain kinds of hosts.

• [ ] create a list of all docs pages that use hosts: all in examples (add as a comment on this issue)
• [ ] update most examples to use a group
• [ ] for any examples where using a group is difficult, add context so users understand the dangers of running a playbook on all hosts in their inventories

(replacement issue for https://github.com/ansible/ansible/issues/75506)