Animation: ---------------------------------------------------------------------
-> zipWith (+) fibs (tail fibs)
-> zipWith (+) (1:fromInteger 1:...) (tail (1:fromInteger 1:...))
-> zipWith (+) (1:1:...) (tail (1:1:...))
-> zipWith (+) (1:1:...) (1:...)
-> 1 + 1:zipWith (+) (1:...) ...
-> 2:zipWith (+) (1:...) ...
-> 2:1 + 2:zipWith (+) ... ...
-> 2:3:zipWith (+) ... ...
-> 2:3:2 + 3:zipWith (+) ... ...
-> 2:3:5:zipWith (+) ... ...
-> 2:3:5:3 + 5:zipWith (+) ... ...
-> 2:3:5:8:zipWith (+) ... ...
-> 2:3:5:8:5 + 8:zipWith (+) ... ...
-> 2:3:5:8:13:zipWith (+) ... ...
-> 2:3:5:8:13:_