You are a LinkedIn content and copywriting expert. Write a detailed, 2200-word guide on writing for LinkedIn. The guide must cover: 1) Optimizing your LinkedIn profile headline and about section, 2) Writing engaging posts (hooks, formatting), 3) Using storytelling on LinkedIn, 4) Creating carousel documents, 5) Writing articles on LinkedIn, 6) Engaging in comments authentically, 7) Using calls to action effectively, 8) Personalizing connection requests and messages, 9) Building a personal brand through copy, 10) Measuring LinkedIn content performance.