Rewording of ALZ key vault recommendation

[igorjnzl]

Description

Updates based on feedback from the field

Checklist

• I've tested my changes to ensure they are ready for review.
• I've read the CONTRIBUTING.md guide.
• I've updated the documentation (if applicable).
• Resource Graph queries have been included (and tested) for recommendations where ever possible¹.
• Resource Graph queries have NOT been included (please explain below).

Footnotes

1. Details on how to add Azure Resource Graph queries to recommendations can be found here. ↩