Create index.html for this Repository

# Create `index.html` for OS Repository with CSS and JavaScript

## Description
Develop an `index.html` page to showcase information about supported operating systems for LinuxDroid. The webpage should be styled using an external `style.css` file and include interactivity through a `linuxdroid.js` file. Ensure the page is visually appealing, easy to navigate, and responsive across devices.

## Tasks
- [ ] Create an `index.html` file with a clean and semantic structure.
- [ ] Style the webpage using an external `style.css` file.
- [ ] Add interactivity using the `linuxdroid.js` file (if necessary).
- [ ] Include a navigation bar for easy access to different sections of the OS list.
- [ ] Ensure responsiveness for various screen sizes (desktop, tablet, mobile).
- [ ] Test the page across different browsers to ensure compatibility.

## Notes
- The CSS file (`style.css`) should follow best practices for styling, including mobile-first design.
- JavaScript (`linuxdroid.js`) should be lightweight and optimized for performance.

Start by inspecting the repository structure and confirm where index.html, style.css, and linuxdroid.js should live. Build the OS information page around the requested navigation, responsive layout, and lightweight interactivity, then verify the page across desktop, tablet, and mobile sizes and browsers.

Written by the indexing model from the issue text.