AlertRuleForm: s/Edit yaml/Edit YAML/ (#67714)

YAML is an acronym and should be uppercased when used in texts.

Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
Co-authored-by: Gilles De Mey <gilles.de.mey@gmail.com>

public/app/features/alerting/unified/components/rule-editor/AlertRuleForm.tsx

@@ -221,7 +221,7 @@ export const AlertRuleForm = ({ existing, prefill }: Props) => {
               onClick={() => setShowEditYaml(true)}
               disabled={submitState.loading}
             >
-              Edit yaml
+              Edit YAML
             </Button>
           )}
           <Button