Add security.md, and tidelift bage

Author: Carreau

README.md

@@ -3,6 +3,7 @@
 [![Tests](https://github.com/ipython/traitlets/actions/workflows/tests.yml/badge.svg)](https://github.com/ipython/traitlets/actions/workflows/tests.yml)
 [![Test downstream projects](https://github.com/ipython/traitlets/actions/workflows/downstream.yml/badge.svg)](https://github.com/ipython/traitlets/actions/workflows/downstream.yml)
 [![Documentation Status](https://readthedocs.org/projects/traitlets/badge/?version=latest)](https://traitlets.readthedocs.io/en/latest/?badge=latest)
+[![Tidelift](https://tidelift.com/subscription/pkg/pypi-traitlets)](https://tidelift.com/badges/package/pypi/traitlets?style=flat)
 
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SECURITY.md

@@ -0,0 +1,11 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+All IPython and Jupyter security are handled via security@ipython.org. 
+You can find more information on the Jupyter website. https://jupyter.org/security
+
+## Tidelift
+
+We are also lifting IPython via Tidelift, you can also report security concern via the [tidelift platform](
+https://tidelift.com/security).