Add copy button to API references

[AnisTss]

Feature Description

I found myself using mouse selection a lot to copy module imports, It would be nice to see a copy icon button in API imports section.

[hadzhiyski]

Hello,

I believe this will require a change in angular/components as well, because the docs are generated there. Custom component might be a good solution to wrap the import as it is now and the "copy to clipboard" button.

@Splaktar please advice if I am looking in the right direction. If it is so, I will submit a PR in both repositories.