Add CTA button to the library

[huyenltnguyen]

Description

I'm wondering if we should add the CTA button to the library.

We are currently using this button in:

• /learn
  • 
  • 
• /news
  • 

If we do want to bring this button into the library, I'd propose keeping it a standalone component, rather than a variable of Button. This allows us to add customization to the component more freely, without worrying it breaking the consistency with the other button variants.