Update docs

Author: rnag

README.md

@@ -1,3 +1,5 @@
+<!--intro-start-->
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 # Secrets Cache
 
 [![PyPI version](https://img.shields.io/pypi/v/secrets-cache.svg)](https://pypi.org/project/secrets-cache/)
@@ -17,6 +19,8 @@ Cache secrets locally from AWS Secrets Manager and other secret stores, with opt
 * Free software: MIT License
 * Documentation: https://secrets-cache.readthedocs.io
 
+<!--intro-end-->
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 ## Installation
 
 Install the base package (minimal, Lambda-friendly):