Add workflow

Author: sebromero

.github/workflows/yamllint.yml

@@ -16,4 +16,8 @@ jobs:
           yamllint_comment: true
           yamllint_config_filepath: 'yamllint-config.yml'
         env:
-          GITHUB_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: 'Schema Validation'
+        run: |
+          npm i -g yaml-schema-validator
+          schema validate -e -f package-list.yaml -s schema.yml