v1.0.1 of celestrak

A pure-Dart client for fetching, parsing, and caching satellite TLE and OMM orbital data from CelesTrak and Space-Track. No Flutter dependency. Changelog excerpt: ### Added - example/main.dart— runnable CLI script demonstrating every public API: fetchByNoradId, fetchCategory, fetchCategoryByGroup, fetchByName, fetchByIntlDesignator, cacheAge, clearCache, isStale, and all cache control parameters (allowStale, forceCache, ttl).