### Changes:
- Added `rollup.unified.js` for building a unified bundle with environment detection (Node.js, Browser, Serverless).
- Added `rollup_config.js` for browser-specific bundle configurations.
- Created `tsconfig.browser.json` for browser builds and `tsconfig.unified.json` for unified builds.
- Implemented custom Rollup plugins:
- **`fixThisReferences`**: Resolves `this` reference issues in TensorFlow files.
- **`nodeModuleShims`**: Provides empty shims for Node.js built-in modules in browser environments.
- Updated dependencies in `package-lock.json` to include Rollup plugins and updated `buffer` dependency for polyfills.
- Created `src/unified.ts` as the unified library entry point with dynamic environment detection.
### Purpose:
- Introduced a unified and browser-compatible build pipeline to ensure `Brainy` can seamlessly operate across multiple environments (Node.js, Browser, Serverless).
- Resolved compatibility issues with Node.js modules and specific library builds.
- Enhanced flexibility and usability for developers working in diverse runtime environments.
