Merge pull request TYPO3-Documentation#42 from TYPO3-Documentation/mi…

…grate_to_main

Add note about changelog indexing to readme

README.rst

@@ -88,3 +88,12 @@ Removing index to start fresh
 
 If you want to start with fresh Elasticsearch index locally, you can use chrome extensions
 like `Elasticvue` to clear/drop Elasticsearch index if necessary.
+
+Indexing Core changelog
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Core changelog is treated as a "sub manual" of the core manual. To index it, just run indexing for `cms-core` manual.
+
+To avoid duplicates search is indexing Core changelog only from "main" version/branch of the core documentation.
+E.g. when you run ``./bin/console docsearch:import c/typo3/cms-core/main/`` then the changelog for all versions will be indexed,
+but if you run `./bin/console docsearch:import c/typo3/cms-core/12.4/` the changelog will NOT be indexed.