Add features and limitations to the project.

Also update the types to be stricter.

Add tests related to error handling.

Traditional British long count is available for systems.

Only largest millia should remove prefix when group is 001.

Make short millia parse and stringify correctly.

Add namespace for short/long count. Also manage conversion configs and defaults.

There is only a certain string length allowed to convert parsed numbers to bigint.

Ensure strings are properly sanitized before processing.

Use bigint for place values to be more adaptable with longer inputs.

Put functions with different purposes into their own files.

Use appropriate place instead of smallest group when creating placeholder groups between actual groups.

Make group management more readable.

Formal English hyphenates tens names.

Address errors with gapped groups.

Ensure digits parse correctly when there are gaps.

Make code more cleaner when parsing.

Format more sections of the code.

Include parse and stringify functions for American short-count locale.