Complete JS style documentation for artwork.js (#3764)

* Added JSDoc style documentation

* Added JSDoc style documentation

* Removed the definition which belonged only to EnvelopBlock

* Added appropriate JSDoc

* Added further JS Documentation

* Completed JS style documentation for WidgetBlocks.js

* Started adding comments for activity.js and temperament.js

* Added further activity.js

* JS Docs added for activity.js

* added JS documentation for activity.js

* Rectified and added some documentations

* Completed Documentation for artwork.js

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Co-authored-by: Walter Bender <[email protected]>