Docs: comprehensive API reference matching README transpilation tables

API page now covers all categories: types, arithmetic, math, 1D arrays,
ND arrays, higher-order functions, strings, broadcasting, control flow,
functions/structs, collections, IO, construction, package registry,
plus "not yet transpiled" and "will not transpile" sections.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Dale-Black