Add changelog

changelog/unreleased/app-registry-order.md

@@ -0,0 +1,12 @@
+Enhancement: Default AppProvider on top of the providers list
+for each mime type
+
+Now for each mime type, when asking for the list of mime types,
+the default AppProvider, set both using the config and the 
+SetDefaultProviderForMimeType method, is always in the top of the
+list of AppProviders.
+The config for the Providers and Mime Types for the AppRegistry changed,
+using a list instead of a map. In fact the list of mime types returned by
+ListSupportedMimeTypes is now ordered according the config.
+
+https://github.com/cs3org/reva/pull/2138