Revise docs.

doc/src/language/overload.md

@@ -10,13 +10,20 @@ New definitions _overwrite_ previous definitions of the same name and number of
 
 ```rust
 fn foo(x,y,z) { print("Three!!! " + x + "," + y + "," + z) }
+
 fn foo(x) { print("One! " + x) }
+
 fn foo(x,y) { print("Two! " + x + "," + y) }
+
 fn foo() { print("None.") }
+
 fn foo(x) { print("HA! NEW ONE! " + x) }    // overwrites previous definition
 
 foo(1,2,3);     // prints "Three!!! 1,2,3"
+
 foo(42);        // prints "HA! NEW ONE! 42"
+
 foo(1,2);       // prints "Two!! 1,2"
+
 foo();          // prints "None."
 ```