Add CodeQL workflow and update project metadata

[coliff]

• Introduces a CodeQL analysis GitHub Actions workflow for security and quality scanning.
• Updates the README to reference the correct upstream project.
• Refactors index.html for improved semantics and accessibility, including header/main elements and image attributes.
• Cleans up and reorders package.json fields, adds 'private' flag, and makes minor metadata adjustments.

[Copilot]

Pull Request Overview

This PR adds security analysis capabilities and improves project accessibility. The changes introduce CodeQL workflow for automated security scanning, update project metadata for better organization, and enhance HTML semantics for improved accessibility.

• Introduces CodeQL GitHub Actions workflow for security and quality analysis
• Refactors HTML structure using semantic elements and improves accessibility
• Reorganizes package.json fields and adds private flag

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
.github/workflows/codeql-analysis.yml	Adds CodeQL security analysis workflow
index.html	Improves semantic HTML structure and accessibility with header/main elements
package.json	Reorders fields, adds private flag, and cleans up metadata
README.md	Updates reference to correct upstream project

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[github-advanced-security]

This pull request sets up GitHub code scanning for this repository. Once the scans have completed and the checks have passed, the analysis results for this pull request branch will appear on this overview. Once you merge this pull request, the 'Security' tab will show more code scanning analysis results (for example, for the default branch). Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results. For more information about GitHub code scanning, check out the documentation.

[roblarsen]

Thanks! I haven't looked at this in years.