Add Tasq introduction video

[version-1]

Add the Tasq introduction video

Summary

Add the prepared Tasq introduction video near the top of the repository README and documentation site overview so visitors can quickly see the product in action.

主な変更点:

• Copy the 9.5 MB introduction video into the Docusaurus static assets.
• Add a clickable thumbnail and explicit video link to the English and Japanese repository READMEs.
• Embed the video in the English and Japanese docs-site overview pages.

チケットへのリンク

ここはまだない

やったこと

• Added docs/site/static/video/tasq-intro.mp4.
• Added the supplied thumbnail as docs/site/static/img/tasq-thumbnail.png.
• Linked the README thumbnail and accompanying text to the supplied GitHub user attachment because GitHub README does not embed the video player.
• Added accessible fallback links inside each video element.
• Used the configured /tasq/ base URL for docs-site video paths.

動作確認

• npm --prefix docs/site run build
• git diff --check origin/main...HEAD
• Confirmed the generated English and Japanese HTML contains the video element.
• Confirmed the source and copied video SHA-256 hashes match.

レビュー & 動作確認 チェックリスト

• README rendering - Confirm the clickable thumbnail and video link appear near the top of both READMEs on GitHub.
• Docs-site rendering - Confirm the player appears on both localized overview pages.
• Playback - Confirm the MP4 loads and plays from the published static asset path.

推奨テスト計画:

1. Open the repository README and follow the thumbnail or text link to the introduction video.
2. Open /tasq/ and /tasq/ja/ in the built documentation site.
3. Play the video on both pages and confirm the fallback link targets the local docs asset.

その他気になることや相談ごと

The video adds approximately 9.5 MB to the repository history.

Requested by: @version-1