Add a copy to clipboard button to code blocks

[johnbillion]

Many web services display a "Copy to clipboard" button on the right hand side of a code block. It would be great to have the same on code blocks that appear on the Make sites, and maybe even the developer reference.

[tellyworth]

This is already the case in the Developer reference, for example: ​https://developer.wordpress.org/reference/functions/add_settings_section/#more-information

I'll look into whether we can enable the same code syntax highlighter plugin on Make sites.

[tellyworth]

There's more to it than just enabling the plugin on Make sites. The Developer reference has some custom JS that adds copy and expand buttons:

​https://github.com/WordPress/wporg-developer/blob/trunk/source/wp-content/themes/wporg-developer-2023/js/function-reference.js#L30-L99

@ryelle what's your take on the best way to make that feature available elsewhere? Do we need a second companion plugin for code-syntax-block that would incorporate those buttons and other customizations for use across the site?