Listed packages may not comply with spec

[ChrisKeefe]

The specification README lists many packages that are not compliant with stated specifications.

Regardless of your feelings on monotonicity (#11, #40, etc), the current spec claims ULIDs provide it, and that they throw an error on overflow. Many listed packages do not implement monotonicity, do not throw, or implement it incorrectly (e.g. by incrementing the timestamp).

Recommended resolutions

• modify the spec (e.g. clarifying whether sections are optional), and/or
• clarify which listed implementations are fully compliant

E.g. a column in the README table describing whether a package implements monotonicity per spec would be useful to potential users