Copy codeblock contents to clipboard

[JammyDodger]

Just a little extra announcement to append to this…

@justin

This feature is off by default, but if your community could benefit from it, you can turn it on by enabling the show copy button on codeblocks site setting.

The setting has proved to be so useful and universally lauded that it is now not only default on but also tucked away as a hidden site setting:

FIX: enable copy code block by default (#23662)