Update 1_8_Classes.ipynb

Improved formatting.

python/1_8_Classes.ipynb

@@ -41,7 +41,7 @@
     "The first argument of instance class method is self, that refers to the current instance of the class.\n",
     "There is a special method, __init__ that initializes the object. It is like a constructor, but the object is already created when __init__ is called.\n",
     "\n",
-    "Instance attributes are define as self.variables. (self is the same than this in Java)."
+    "Instance attributes are define as *self.variables*. (self is the same than this in Java)."
    ]
   },
   {