Update release notes for Fleet 4.83.0 (#43276)

Pull "YAML validation" section up to the top and warn users that they
might run into new errors on upgrade.

articles/fleet-4.83.0.md

@@ -8,10 +8,20 @@ Fleet 4.83.0 is now available. See the complete [changelog](https://github.com/f
 
 ## Highlights
 
+- YAML validation for extraneous keys
 - macOS Recovery Lock passwords
 - Patch policies for Fleet-maintained apps
 - Lock end user info during macOS setup
-- YAML validation for extraneous keys
+
+### YAML validation for extraneous keys
+
+Fleet now returns a clear error when a YAML file contains an unrecognized or misspelled key. Previously, Fleet silently ignored unknown keys, which could cause configurations to take effect without the intended settings applied.
+
+This is especially useful for catching typos and errors in AI-generated GitOps PRs before a misconfiguration takes effect.
+
+> **Note:** After upgrading, you may encounter new errors from previously ignored misspelled or misplaced keys. [Reach out to Fleet](https://fleetdm.com/support) if you need help.
+
+GitHub issue: [#40496](https://github.com/fleetdm/fleet/issues/40496)
 
 ### macOS Recovery Lock passwords
 
@@ -35,12 +45,6 @@ To configure, head to **Controls > Setup experience** and expand the new **Advan
 
 GitHub issue: [#38669](https://github.com/fleetdm/fleet/issues/38669)
 
-### YAML validation for extraneous keys
-
-Fleet now returns a clear error when a YAML file contains an unrecognized or misspelled key. Previously, Fleet silently ignored unknown keys, which could cause configurations to take effect without the intended settings applied. This is especially useful for catching typos and errors in AI-generated GitOps PRs early, before a misconfiguration silently takes effect.
-
-GitHub issue: [#40496](https://github.com/fleetdm/fleet/issues/40496)
-
 ## Changes
 
 ### IT Admins