Added nbstripout to pre-commit

.pre-commit-config.yaml

@@ -20,3 +20,8 @@ repos:
     rev: v3.15.0
     hooks:
     -   id: pyupgrade
+
+-   repo: https://github.com/kynan/nbstripout
+    rev: 0.7.1
+    hooks:
+    -   id: nbstripout