Move a code block to the right place

Author: mortenpi

README.md

@@ -52,6 +52,12 @@ Poly(0.5 - 0.5x^2)
 ```
 
 Note that operations involving polynomials with different variables will error.
+```julia
+julia> p = Poly([1, 2, 3], :x)
+julia> q = Poly([1, 2, 3], :s)
+julia> p + q
+ERROR: Polynomials must have same variable.
+```
 
 To get the degree of the polynomial use `degree` method
 ```
@@ -65,13 +71,6 @@ julia> degree(p-p)
 0
 ```
 
-```julia
-julia> p = Poly([1, 2, 3], :x)
-julia> q = Poly([1, 2, 3], :s)
-julia> p + q
-ERROR: Polynomials must have same variable.
-```
-
 #### polyval(p::Poly, x::Number)
 Evaluate the polynomial `p` at `x`.