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 to understand where the new page should live and whether style.css or linuxdroid.js already exists. Create index.html with semantic OS information and navigation, connect the external CSS and JavaScript files, and verify responsive layouts and browser behavior across desktop, tablet, and mobile sizes.

Written by the indexing model from the issue text.