Add docs warnings for older package being superseded

Author: sr-murthy

README.md

@@ -20,7 +20,10 @@
 
 A lightweight Python client library for the UK [Financial Services Register](https://register.fca.org.uk/s/) [RESTful API](https://register.fca.org.uk/Developer/s/).
 
-The [PyPI package](https://pypi.org/project/financial-services-register-api) is currently at version `0.5.1`.
+The [PyPI package](https://pypi.org/project/financial-services-register-api) is currently at version `1.0.0`.
+
+> [!WARNING]
+> The new associated PyPI package <span class="title-ref">financial-services-register-api</span> supersedes the older package <span class="title-ref">fsrapiclient</span>, which will no longer be published. Existing versions of the older package may be retracted in the future. Please use the new package.
 
 The Financial Services Register, or FS Register, is a **public** database of all firms, individuals, funds, and other entities, that are either currently, or have been previously, authorised and/or regulated by the UK [Financial Conduct Authority (FCA)](https://www.fca.org.uk) and/or the [Prudential Regulation Authority (PRA)](http://bankofengland.co.uk/pra).
 

docs/index.rst

@@ -10,6 +10,10 @@ A Python client library for the UK `Financial Services Register <https://registe
 
 The `PyPI package <https://pypi.org/project/financial-services-register-api>`_ is currently at version `1.0.0`.
 
+.. warning::
+
+   The new associated PyPI package `financial-services-register-api` supersedes the older package `fsrapiclient`, which will no longer be published. Existing versions of the older package may be retracted in the future. Please use the new package.
+
 The Financial Services Register (alternatively, FS Register), is a **public** database of all firms, individuals, funds, and other entities, that are either currently, or have been previously, authorised and/or regulated by the UK `Financial Conduct Authority (FCA) <https://www.fca.org.uk>`_ and/or the `Prudential Regulation Authority (PRA) <http://bankofengland.co.uk/pra>`_.
 
 .. note::