docs: improve index

[daniqss]

Pull Request

What does this PR introduce?

Clearly describe what this PR changes or adds.
Improve documentation index

Scope of change

Select the affected area(s):

• Builder (Markdown → HTML)
• Pseudocode Lexer
• Pseudocode Parser / AST
• Interpreter / Runtime
• Debugger (step execution)
• CLI
• Documentation
• Tests

Code Quality Checklist

Please confirm that you have followed the project's quality standards:

• I have run npm run lint, npm run format and fixed any errors.
• I have run ruff check --fix . and ruff format ..
• My commit messages follow the Conventional Commits format.

How has this been tested?

• Manual testing
• Unit tests added/updated
• Existing tests pass
• Verified generated HTML output
• Verified step-by-step debugger behavior
• N/A

Explain briefly what was tested.

Breaking changes?

• No
• Yes (explain below)

If yes, describe:

• What breaks
• Why it breaks
• Migration steps (if needed)

Additional notes

close #39