Custom CSS/JS injection via config

[tacheraSasi]

Feature: Custom CSS/JS Injection

Support a .mdcli.yaml config with extra_css and extra_js fields for user customization.

Details

• Read from .mdcli.yaml in the served directory
• Support extra_css: ["./custom.css", "https://example.com/style.css"]
• Support extra_js: ["./custom.js"]
• Inject custom stylesheets and scripts into the served HTML pages
• Support inline CSS/JS blocks in config as well
• Watch custom CSS/JS files for changes and trigger reload
• Document available CSS custom properties for easy theming

Why

Users need the ability to customize appearance beyond built-in themes without forking the project.