items on arangodb-docker description page are dated

[williamvm]

Hello some items are dated or wrong with current 3.6 images, please update. https://hub.docker.com/_/arangodb/

1. in Persistent Data first alinea, last sentence "The default choice is mmfiles" better "Starting with 3.6 the default configuration is rocksdb" 2. in Persistent Data last alinea linked blog articles are dated and wrong by now. better the offical Docker docs on Storage and/or popular article like Stephens Blog 3. in Persistent Data, Using as a base image dated, drop the whole subject