docs: fix incorrect length range in parse() error message

[malapeiro]

Summary

parse() accepts strings with length between 1 and 100, but the error
message and JSDoc state the range is "between 1 and 99". A string of
exactly 100 characters is valid input and parses successfully,
contradicting the documented contract.

Notably, PR #89 (which introduced this limit) is titled "Limit str to 100",
so the current validation reflects the original intent — the message text
is what's incorrect.

Reproduction

import { parse } from './src/index.ts';

// 100 chars — parses fine (proving the actual limit is 100)
parse('1' + '0'.repeat(97) + 'ms'); // → 1e+97

// 101 chars — throws with the misleading message
parse('1' + '0'.repeat(98) + 'ms');
// Error: Value provided to ms.parse() must be a string with length
// between 1 and 99. value="..."

Suggested fix

Update the error message and JSDoc to say "between 1 and 100" instead of
"between 1 and 99" (one line in src/index.ts).