Change playbook name

Author: JustinPihony

.github/workflows/PullRequestValidator.yml

@@ -15,4 +15,4 @@ jobs:
       - name: Install Antora and Lunr
         run: npm i antora @antora/lunr-extension
       - name: Run Antora
-        run: npx antora antora-playbook.yml
+        run: npx antora playbook.yml