Provide Jupyter notebooks that explain Catmandu usage

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The command line client could be explored with the Jupyter bash kernel and Catmandu pre-installed. The Perl kernel might provide a REPL for Perl code using Catmandu.

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A very convenient way to teach and allow trying out Catmandu could be achieved with binder. It requires a Dockerfile to install dependencies which would include Catmandu packages. See binder documentation and a full sample for perl6 - I have not found a sample for Perl 5 yet.

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Here we go! (see https://github.com/LibreCat/catmandu-notebook#readme)