Status: Tutorial coverage of various Metador topics

[apirogov]

We need tutorials both for "developers" (people writing plugins), and later for "users" (who just use existing things, without implementing new plugins).

Developer tutorials:

• Basic usage of MetadorContainer ("low-level" but keep it simple, preparation for schema or packer writers)
• Creation of new plugins, in general (poetry, entry point registration, consulting the plugingroup requirements)
• Schemas Part 1 (inheritance, types, etc)
• Schemas Part 2 (semantics, later also add docs on JSON Schema interop Evaluate, improve and document compatibility with JSON Schema #59)
• Schemas Part 3 (Custom parsers for schemas, metadata normalization)
• Using and writing Harvesters (including logic of partial updates)
• Developing a Packer (could walk through example packer)
• Developing new Widgets
• Extra: Tutorial for IH5(MF)Record and how immutable HDF5 works (orthogonal to the rest)

User tutorials:

• Using packers: Pack a dataset based on a source directory
• Using widgets: Visualize data in a container in a Jupyter notebook