Create some way for subsites to pull Event banner data from CNCF.io

[cjyabraham]

• Create some kind of API call that returns a json of Event ad data so the same widget can be recreated on subsites; we'll need to see if sites like the store can support this kind of code
• JSON could include desktop image url, mobile image url, alt text, and event link for each entry
• As a simpler option we could not bother with the whole slider but just display the soonest event