Add warning for aktualizr-lite update

[kprosise]

Brief warning added as single line.

QA steps: viewed rendered html.

This commit addresses FFTK-2965

Readiness

• Merge (pending reviews)
• Merge after date or event
• Draft

Overview

Why merge this PR? What does it solve?

Checklist

Optional. Add a 'x' to steps taken.
You can fill this out after opening the PR. "Did I..."

• Run spelling and grammar check, preferably with linter.
• Avoid changing any header associated with a link/reference.
• Step through instructions (or ask someone to do so).
• Review for wordiness
• Match tone and style of page/section.
• Run make linkcheck.
• View HTML in a browser to check rendering.
• Use semantic newlines.
• follow best practices for commits.
  • Descriptive title written in the imperative.
  • Include brief overview of QA steps taken.
  • Mention any related issues numbers.
  • End message with sign off/DCO line (-s, --signoff).
  • Sign commit with your gpg key (-S, --gpg-sign).
  • Squash commits if needed.
• Request PR review by a technical writer and at least one peer.

Comments

Any thing else that a maintainer/reviewer should know.
This could include potential issues, rational for approach, etc.

[doanac]

Docs for 1bf9499 are browsable at: https://ci.foundries.io/projects/fio-docs/builds/2560/docs/artifacts/html/index.html

[doanac]

Docs for abf0250 are browsable at: https://ci.foundries.io/projects/fio-docs/builds/2562/docs/artifacts/html/index.html