Transpose an arbitrarily sized rectangular Matrix.




  [ ' [ [ ] ] 
    over 0 peek size of 
    [] rot
    witheach join
    witheach
      [ dip behead 
        nested join
        nested join ] ] is transpose ( [ --> [ )
 
  ' [ [ 1 2 ] [ 3 4 ] [ 5 6 ] ] 
  dup echo cr cr
  transpose dup echo cr cr
  transpose echo cr