docs: Add deprecation notice to readme (#170)

README.rst

@@ -1,5 +1,19 @@
-edX Analytics API Client |build-status| |coverage-status|
-=========================================================
+edX Analytics API Client
+========================
+
+DEPRECATION NOTICE
+------------------
+
+The Insights product and associated repositories are in the process of being
+deprecated and removed from service. Details on the deprecation status and
+process can be found in the relevant `Github issue <https://github.com/openedx/public-engineering/issues/221>_`.
+
+This repository may be archived and moved to the openedx-unsupported
+Github organization at any time.
+
+The following sections are for historical purposes only.
+
+
 
 The edX Analytics API Client (henceforth, client) allows users to retrieve data from the edX data warehouse. Currently,
 the client supports retrieving course activity and enrollment data. By default, all data is returned in the JSON format.
@@ -8,20 +22,3 @@ Enrollment data may also be retrieved in the CSV format by changing the data_for
 Testing
 -------
     $ make validate
-
-
-How to Contribute
------------------
-
-Contributions are very welcome, but for legal reasons, you must submit a signed
-`individual contributor's agreement`_ before we can accept your contribution. See our
-`CONTRIBUTING`_ file for more information -- it also contains guidelines for how to maintain
-high code quality, which will make your contribution more likely to be accepted.
-
-.. _individual contributor's agreement: http://code.edx.org/individual-contributor-agreement.pdf
-.. _CONTRIBUTING: https://github.com/openedx/.github/blob/master/CONTRIBUTING.md
-
-.. |build-status| image:: https://github.com/openedx/edx-analytics-data-api-client/workflows/Python%20CI/badge.svg?branch=master
-   :target: https://github.com/openedx/edx-analytics-data-api-client/actions?query=workflow%3A%22Python+CI%22
-.. |coverage-status| image:: https://coveralls.io/repos/edx/edx-analytics-data-api-client/badge.png
-   :target: https://coveralls.io/r/edx/edx-analytics-data-api-client