WebTorrent test fixtures

Provides sample torrent files and content for testing WebTorrent-based applications. Current version 2.0.3, released on npm with a mature and stable API. Includes common torrent fixtures (e.g., 'leaves' torrent with its content) and metadata. No major release cadence; maintained as part of the WebTorrent ecosystem. Key differentiator: standardized, ready-to-use torrent test data with known infohashes and file structures, eliminating the need to generate test fixtures manually.