RFC: Fully enabling --enable-experimental-code-block-annotations

I'm not sure how many folks have had much of chance to use --enable-experimental-code-block-annotations to add in the copy-to-clipboard or the extended highlighting capability for code blocks. Since it's a Swift 6.3 feature, it's comparatively new. I'd like to propose that we remove the experimental from this feature capability, and further - float the idea of enabling it by default. This has a notable effect that will change all the existing content to enable a copy-to-clipboard functionality ...