What would you like to be added:
I propose the addition of a clipboard copy feature for the content within code blocks in CodePair view mode. This feature is also implemented in the official Yorkie web documentation, where users can click to copy the contents of code blocks with a simple action.

Implementing this functionality would eliminate the need for manual dragging to select text, making it easier and more convenient for users to copy the desired content.

Why is this needed:
Enhancing usability and improving the user experience by providing a straightforward method to copy code block content efficiently.

Additional Information: