docs(readme): surface corpus preview

[shaypal5]

Summary

Turns the GitHub README into a concise gateway for first-time corpus consumers, with the live docs site and a real waveform preview visible near the top.

What changed

• Added docs, CI, license, and audio-format badges.
• Added the required creator attribution near the top and a bottom ## Credits section.
• Surfaced the live MkDocs consumer guide prominently near the top.
• Added a data preview section using the existing tracked waveform image for sp_sv_a_0001_00.
• Added a compact corpus facts table covering batch size, audio format, data source, product contexts, generator, and delivery log.
• Reorganized onboarding links into a Where to Start table that points users to the docs site before deeper local files.
• Preserved the important contributor/agent constraints about not hand-editing assets, WAV files, or corpus metadata.
• Updated repository metadata with the live Pages homepage and dataset/audio/MkDocs topics.

Impact

Documentation and repository metadata only. No audio, labels, delivery records, cache files, or corpus data are changed.

Milestone

Checked open milestones: this repository currently has no open milestones, so no milestone was assigned.

Validation

• curl -I -L https://datahackil.github.io/avdp-synth-corpus/ returned HTTP/2 200.
• git diff --check passed.
• Verified docs/assets/sp_sv_a_0001_00_waveform.png exists and is referenced from the README.
• Verified creator attribution appears exactly twice, using the requested top-line and bottom Credits formats.
• pre-commit run --all-files was attempted; it fails on existing mkdocs.yml Material extension tags that the generic YAML hook cannot construct. This PR stages only README.md, so the commit hook did not run that unchanged YAML file.

[github-actions]

pr-agent-context report:

This run includes a failing check on PR #8 in repository https://github.com/DataHackIL/avdp-synth-corpus

Diagnose and fix the failing checks below, then push all of these changes in a single commit.

# Failing Checks

## FAIL-1
Type: Commit status
Context: pre-commit.ci - pr
Status: failure
URL: https://results.pre-commit.ci/run/github/1210843386/1780259601.c9guvkh7SnG3eJI4quspFg

Summary:
    checks completed with failures

Run metadata:

Tool ref: v4
Tool version: 4.0.21
Trigger: pull request opened
Workflow run: 26723727474 attempt 1
Comment timestamp: 2026-05-31T20:33:43.715198+00:00
PR head commit: f4c0bd13b7840c28622f2b78440085082dcd2c5e