Issue #3316980 by dineshreddymathuku, ressa, dcam, sunidhinegi31: Create README.md file

README.md

+# Aggregator
+
+Use the Aggregator module to ingest content from RSS feeds into your site. This
+is the same module that was in Drupal core until version 10.0. It was deprecated
+in Drupal core version 9.4 and moved to contrib. It is used to power
+[Drupal planet](https://www.drupal.org/planet) on
+[Drupal.org](https://drupal.org).
+
+
+## Requirements
+
+No other modules are required.
+
+
+## Installation
+
+Install as you would normally install a contributed Drupal module. For further
+information, see
+[Installing Drupal Modules](https://www.drupal.org/docs/extending-drupal/installing-modules).
+
+
+## Configuration
+
+1. Enable the module under Administration > Extend
+1. Add and manage feeds at Administration > Configuration > Web services >
+   Aggregator (/admin/config/services/aggregator)
+1. Configure settings for all feeds at Administration > Configuration > Web
+   services > Aggregator (/admin/config/services/aggregator/settings)
+
+
+## Maintainers
+
+- Lee Rowlands - [larowlan](https://www.drupal.org/u/larowlan)
+- David Cameron - [dcam](https://www.drupal.org/u/dcam)