add examples to black formatting check

Author: Max Wang

.azdo/ci-pr.yaml

@@ -47,7 +47,7 @@ extends:
           displayName: 'Install dependencies'
         
         - script: |
-            black src tests --check
+            black src tests examples --check
           displayName: 'Check format with black'
         
         - script: |

.github/workflows/python-package.yml

@@ -32,7 +32,7 @@ jobs:
     
     - name: Check format with black
       run: |
-        black src tests --check
+        black src tests examples --check
     
     - name: Lint with flake8
       run: |