Documentation for 5-Day Weather Forecast Web App

I need technical documentation only for a lightweight weather forecasting web application built with HTML, CSS, and vanilla JavaScript (no frameworks).

I do NOT need the actual application code developed.

The documentation should describe how to build a web app that:

Fetches real-time 5-day forecast data from a reliable weather API
Displays temperature, humidity, and wind speed
Shows the data in:
A clean list/card layout
A simple chart (line or bar chart)
What the Documentation Should Include
Recommended project structure
Suggested HTML layout/components
CSS styling approach for responsive design
JavaScript architecture and fetch flow
How to integrate a weather API
Error handling approach
Suggested chart implementation approach
DOM update workflow
Deployment recommendations for static hosting
README-style setup instructions
API key configuration guidance
Notes on how to switch weather providers later
Demo/mockup pictures or UI reference images included within the document to illustrate the expected layout and user interface
Deliverables

The final deliverable should be clear, beginner-friendly documentation explaining:

System design
Application flow
Recommended implementation steps
Best practices

No coding or implementation is required.