[AIRFLOW-XXXX] Add useful tips to first PR msg (apache#7082)

.github/boring-cyborg.yml

@@ -152,6 +152,19 @@ firstPRWelcomeComment: |
   If you have any issues or are unsure about any anything please check our
   Contribution Guide (https://github.com/apache/airflow/blob/master/CONTRIBUTING.rst)
 
+  Here are some useful points:
+  - Pay attention to the quality of your code (flake8, pylint and type annotations). Our [pre-commits](
+  https://github.com/apache/airflow/blob/master/STATIC_CODE_CHECKS.rst#prerequisites-for-pre-commit-hooks)
+  will help you with that.
+  - In case of a new feature add useful documentation (in docstrings or in `docs/` directory).
+  Adding a new operator? Consider adding an example DAG that shows how users should use it.
+  - Consider using [Breeze environment](https://github.com/apache/airflow/blob/master/BREEZE.rst) for testing
+  locally, it’s a heavy docker but it ships with a working Airflow and a lot of integrations.
+  - Be patient and persistent. It might take some time to get a review or get the final approval from
+  Committers.
+
+  Apache Airflow is a community-driven project and together we are making it better 🚀.
+
   In case of doubts contact the developers at:
   Mailing List: [email protected]
   Slack: https://apache-airflow-slack.herokuapp.com/