Adds a Discord entry to the Getting Started list in `README.md` and
replaces the standalone "View on GitHub" link in `docs/home.mdx` with a
sentence inviting readers to join on GitHub or Discord.
Also applies minor formatting cleanup in `README.md`: bolds the link
text and switches hyphens to em dashes for consistency.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add top-level LICENSE file (Apache 2.0) and a License section to
README documenting the dual-license structure: Apache 2.0 for code,
CC-BY-4.0 for documentation.
Closes#121