modify docstrings

Author: ytdHuang

src/qobj/quantum_object_evo.jl

@@ -35,12 +35,9 @@ Quantum Object:   type=Operator   dims=[10, 2]   size=(20, 20)   ishermitian=tru
 ScalarOperator(0.0 + 0.0im) * MatrixOperator(20 × 20)
 ```
 
-If there are more than 2 operators, we need to put each set of operator and coefficient function into a two-element `Tuple`, and put all these sets together in a large `Tuple`:
+If there are more than 2 operators, we need to put each set of operator and coefficient function into a two-element `Tuple`, and put all these `Tuple`s together in a larger `Tuple`:
 
 ```
-julia> coef2(p, t) = sin(t)
-coef2 (generic function with 1 method)
-
 julia> σm = tensor(qeye(10), sigmam())
 Quantum Object:   type=Operator   dims=[10, 2]   size=(20, 20)   ishermitian=false
 20×20 SparseMatrixCSC{ComplexF64, Int64} with 10 stored entries:
@@ -50,6 +47,9 @@ Quantum Object:   type=Operator   dims=[10, 2]   size=(20, 20)   ishermitian=fal
 ⎢⠀⠀⠀⠀⠀⠀⠂⡀⠀⠀⎥
 ⎣⠀⠀⠀⠀⠀⠀⠀⠀⠂⡀⎦
 
+julia> coef2(p, t) = sin(t)
+coef2 (generic function with 1 method)
+
 julia> op1 = QuantumObjectEvolution(((a, coef1), (σm, coef2)))
 Quantum Object:   type=Operator   dims=[10, 2]   size=(20, 20)   ishermitian=true
 (ScalarOperator(0.0 + 0.0im) * MatrixOperator(20 × 20) + ScalarOperator(0.0 + 0.0im) * MatrixOperator(20 × 20))