Fixed comments in the Gorgonia code to go with @dwhitena's comments about idiomatic go comments

Author: chewxy

content/post/deeplearning_in_go_part_1.md

@@ -222,24 +222,25 @@ So instead of the program above, we'd create something like this:
 
 ```go
 func main() {
-// create a graph
+// Create a graph.
 g := G.NewGraph() 
 
-// create a node called "x" with the value 1
+// Create a node called "x" with the value 1.
 x := G.NodeFromAny(g, 1, G.WithName("x")) 
 
-// create a node called "y" with the value 1
+// Create a node called "y" with the value 1.
 y := G.NodeFromAny(g, 1, G.WithName("y")) 
 
 // z := x + y
 z := G.Must(G.Add(x, y)) 
 
-// create a VM to execute the graph
+// Create a VM to execute the graph.
 vm := G.NewTapeMachine(g) 
+
 // Run the VM. Errors are not checked.
 vm.RunAll() 
 
-// print the value of z
+// Print the value of z.
 fmt.Printf("%v", z.Value()) 
 }
 ```