docs: fix README title underlining. 🤦

README.rst

@@ -1,12 +1,12 @@
-⛔️ DEPRECATION WARNING 
-======================
+DEPRECATION WARNING 
+====================
 This repository is deprecated and in maintainence-only operation while we work on a replacement, please see `this announcement <https://discuss.openedx.org/t/deprecation-removal-ecommerce-service-depr-22/6839>`__ for more information.
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+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
 Although we have stopped integrating new contributions, we always appreciate security disclosures and patches sent to `[email protected] <mailto:[email protected]>`__
 
 edX Ecommerce Worker  |Build|_ |Codecov|_
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+=========================================
 .. |Build| image:: https://github.com/edx/ecommerce-worker/workflows/Python%20CI/badge.svg?branch=master
 .. _Build: https://github.com/edx/ecommerce-worker/actions?query=workflow%3A%22Python+CI%22