nomenclature: cleaned up references to spec and containers

The spec is currently called "isArray.js" (which is admittedly
confusing since there is no actual isArray.js source file).
Dropped the wording on "container classes".

Also added links and some explanation of what is in the repo.
README: was getting long. Added TL;DR section.

Also some further README refinement.
Fixed comments in html files.
Split README into three documents.

Spun off Examples and Current Practices so that the
README is more focused.
revision: Renaming to ArrayLike and simplifying spec.

Spec is now simply ArrayLike.js, and the field is
now a simple __ArrayLike boolean. Also refactored
the triplet.js source, and cleaned up all examples.