Explicit field hierarchy and array sub-types (#583)

* Improve readability (#582)

* Improve readability

* replace < and > with &lt; and &gt; for display.

* all fields have a definition

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Co-authored-by: Tom <[email protected]>

* Minor rephrasings

* Remove duplicate of Object definition

* Make field hierarchy explicit

* Adds missing array sub-types

* Fix type Array<ID>

* Update fiedl descriptions for Array<ID>

* Maintain field types alphabetical order

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Co-authored-by: Tom <[email protected]>