Add static Acme Tools site

[possibly6]

Closes #9

Summary

• Adds index.html, about.html, and contact.html at the project root.
• Each page uses valid basic HTML structure with a meaningful <title>.
• Headings, paragraphs, and relative navigation links match the acceptance criteria exactly.
• No JavaScript, no external dependencies, no extra files.

Verification

• git diff --check
• Confirmed all three files exist at root with the required exact strings and relative hrefs (index.html, about.html, contact.html).