tutorial -- convert documentation from tutorial format

i1 : ///-- We can compute $(x+y)^3$ as follows.
     	R = QQ[x,y]
     	(x+y)^3
     	///

o1 = -- We can compute $(x+y)^3$ as follows.
             R = QQ[x,y]
             (x+y)^3
             

i2 : tutorial oo

                                            +---------------+
o2 = {We can compute $(x+y)^3$ as follows., |  R = QQ[x,y]  |}
                                            +---------------+
                                            |  (x+y)^3      |
                                            +---------------+

o2 : List

i3 : peek oo

o3 = {PARA{TEX{"We can compute $(x+y)^3$ as follows."}}, TABLE{class =>
     ------------------------------------------------------------------------
     examples, TR{TD{ExampleItem{"R = QQ[x,y]"}}},
     ------------------------------------------------------------------------
     TR{TD{ExampleItem{"(x+y)^3"}}}}}