[mayankbohradev]

Summary

Add an HTML API reference for the public Python SDK. This closes #61.

The reference shows public modules, their docstrings, and their type annotations.

Changes

• Add pdoc==16.0.0 to docs/requirements.txt. This keeps pdoc out of the SDK runtime dependencies.
• Add scripts/build_api_docs.sh to build the reference in docs/api/.
• Include the top-level, prerecorded, sync, dictation, LLM Gateway, and streaming APIs.
• Make warnings fail the docs build.
• Add a test for key public classes and methods. The test also checks that the internal _audio module is absent.
• Add a GitHub Actions workflow. It runs on pull requests and pushes to master.
• The workflow builds and tests the reference on Python 3.12. It uploads the HTML as an artifact. It does not publish the reference.
• Ignore docs/api/ so generated files are not committed.

Tests

• Docs build: passed locally.
• Docs test: 1 test passed.
• tox -e py312-latest: 742 tests passed. Tox reported 196 warnings.
• Ruff and git diff --check: passed.
• Ruby parsed the workflow YAML. actionlint was not available.