Add ability to display "Copy page" button on blog posts

[Simek]

Why

It would be nice to be able to display the "Copy page" button on blog posts pages, since it might be helpful for some to get the summary of the content using LLMS. Ideally it should be configurable via plugin settings.

Ref:

• https://docusaurus.io/docs/blog
• https://reactnative.dev/blog/2026/06/11/react-native-0.86