Why are Easter eggs called Easter eggs?

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Tags

1. #usually
2. #feature
3. #secret
4. #media
5. #inside
6. #traditional
7. #image
8. #video
9. #computer
10. #easter
11. #intentional
12. #evoke
13. #hidden
14. #screen
15. #program
16. #message
17. #found
18. #software