BUGIX: Fix typo in readme

`Indexing.Indexing.extractAssetContent(value)` › `Indexing.extractAssetContent(value)`

Author: jonnitto

README.md

@@ -370,7 +370,7 @@ Neos:
         'Neos\Media\Domain\Model\Asset':
           elasticSearchMapping:
             type: text
-          indexing: ${Indexing.Indexing.extractAssetContent(value)}
+          indexing: ${Indexing.extractAssetContent(value)}
 ```
 
 or add the attachments content to a fulletxt field in your NodeType configuration: