Another experimental implementation for the Processing part of the manifest

Matt has already added a JS implementation for the 'Processing a Manifest' algorithm[2]. I have also done my own, this time in Typescript[3].

These two implementations (that have been done 100% independently of one another) have already proven very useful; we both hit a number of minor issues when cleaning up [1]. 

Ivan


[1] https://w3c.github.io/pub-manifest/#manifest-processing <https://w3c.github.io/pub-manifest/#manifest-processing>
[2] https://github.com/w3c/pub-manifest/tree/master/experiments/manifest-to-internal-processor <https://github.com/w3c/pub-manifest/tree/master/experiments/manifest-to-internal-processor>
[3] https://github.com/iherman/PubManifest

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Ivan Herman, W3C 
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
ORCID ID: https://orcid.org/0000-0003-0782-2704