spec: extend annotation keywords, array shapes, and fix editorial issues

New keywords: DataSchema, ArrayCoords, ArrayUnits, ArrayFillValue, ArrayChunks, EnumOrdered, TableIndex, TableSortOrder, ListLength

New ArrayShape types: range (compact [start,end] per dim, N from ArraySize, inclusive), circulant, hankel, identity, zero

Tables: add datetime DataType; extend DataInfo recommended properties (License, GeneratedBy, DerivedFrom, SourceFormat)

ArrayType: accept float16/32/64 as aliases for half/single/double

ArrayZipType: adopt Numcodecs identifiers; Blosc2 only with full sub-codec names (blosc2lz4, blosc2zstd, etc.); clarify zlib vs gzip

Fixes: GraphEdges0 self-ref typo, GraphMatrix keyword typos (ArrayTye, missing trailing underscores), LinkNext -> ListNext, duplicate ArrayZipLevel bullet, duplicate ArrayShuffle bullet, merge split .datainfo/.dataschema paragraphs

Author: fangq