Add GitHub Pages landing site with install one-liners and docs hub

[Copilot]

The repo needed a polished landing page that highlights oops, presents one-liner installs for macOS/Linux/Windows, contrasts advantages over thefuck, and links into deeper docs, plus automated GitHub Pages publishing.

• New landing site: Static website/index.html with hero metrics, thefuck migration highlights, feature cards, rule coverage summary, and copy-to-clipboard install one-liners per platform; styled via website/assets/styles.css.
• Docs hub link-out: Added website/docs/index.md to route users to installation, configuration, migration, rules, and architecture guides.
• Publishing workflow: New .github/workflows/gh-pages.yml builds and deploys the website/ directory to GitHub Pages on pushes to main/master or manual dispatch.
• Artifact: Captured website-screenshot.png to illustrate the new landing page.

Example snippet (install + alias):

# macOS / Linux
brew install animeshkundu/tap/oops
eval "$(oops --alias)"

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