feat: update diagram layout

[AykutSarac]

This pull request introduces multiple updates across the project, focusing on enhancing configuration flexibility, improving the editor's UI/UX, and refactoring code for better maintainability. Key changes include updates to environment variables, UI components, and graph rendering logic.

Configuration Updates:

• Updated .env to increase the NEXT_PUBLIC_NODE_LIMIT from 600 to 800 and added a new NEXT_PUBLIC_DISABLE_EXTERNAL_MODE variable in .env.development. These changes allow for more flexibility in node limits and external mode behavior. [1] [2]
• Added a configuration section to the README.md to document how to modify the NEXT_PUBLIC_NODE_LIMIT value.

UI/UX Improvements:

• Replaced the "Nodes" count in the BottomBar with a dropdown menu for selecting file formats, improving usability. [1] [2]
• Enhanced the ExternalMode modal with an accordion-based FAQ and removed the previous styled alert, making the dialog more user-friendly and informative.
• Updated the SearchInput placeholder to dynamically display the correct hotkey based on the user's operating system. [1] [2]

Refactoring and Code Simplification:

• Refactored CustomEdge in the graph view to use edges from the state for determining the target node, replacing DOM-based logic for better reliability.
• Updated ObjectNode to use a more structured approach for rendering rows, replacing the Value tuple with a NodeData-based structure. This improves clarity and maintainability. [1] [2]

Data and Styling Updates:

• Added a new example dataset (example.json) containing structured information about fruits, which can be used for testing or demonstration purposes.
• Adjusted the toolbar to remove the file format dropdown and replaced it with a "Share" button and a "Try Pro" button, aligning with the updated design. [1] [2]