✨ Add Markdown rendering and improve entry display

Introduce `commonmarker` for Markdown support and enhance entry content rendering in various views for better formatting and user experience. ✨ Enhance entry content formatting Improve line ending normalization and highlight search queries in entry list. 💄 Update text area styling for entry form Enhance focus styles for the content text area to improve UI consistency. ✨ Add support for multiple response formats Enhance the show action to respond with HTML, Markdown, JSON, and plain text.