fix link

docs/modules/ROOT/pages/jme3/simpleapplication_from_the_commandline.adoc

@@ -257,7 +257,7 @@ mkdir assets/Textures
 
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-This directory structure will allow xref:core:app/simpleapplication.adoc[SimpleApplication]'s default xref:core:/app/asset_manager.adoc[AssetManager] to load media files from your `assets` directory, like in this example:
+This directory structure will allow xref:core:app/simpleapplication.adoc[SimpleApplication]'s default xref:core:/asset/asset_manager.adoc[AssetManager] to load media files from your `assets` directory, like in this example:
 
 [source]
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