Add Prettier configuration

## Problem We want to maintain a consistent code style without manually formatting files, but Prettier is not yet configured. ## Goal Add Prettier and a configuration file to format our TypeScript, CSS, and Markdown files automatically. ## Where to Look - The root of the repository. ## Suggested Approach 1. Install `prettier` as a dev dependency. 2. Create a `.prettierrc` file with basic rules (e.g., `semi: true`, `singleQuote: true`). 3. Add a `.prettierignore` file to ignore build artifacts. 4. Add a `format` script to `package.json`. ## Acceptance Criteria - [ ] Prettier is installed. - [ ] `.prettierrc` is defined. - [ ] `npm run format` successfully formats all relevant files. ## Testing Modify a file with bad spacing, run `npm run format`, and verify it is corrected. ## Difficulty `Beginner`