Chickadee v0.5.513

Changed

• One typed JupyterLite contents model. The contents routes build one Encodable JupyterContentsModel for files, notebooks and directories, in place of two [String: Any] dictionaries. A JSON file is checked to parse, then its own bytes go into the response, so a large notebook is no longer decoded and encoded again on each request. The keys and values the JupyterLite client reads do not change. (#2308)