fix mismatch import in the documentation (#176)

Author: andriyor

docs/_docs/comparison.rst

@@ -102,7 +102,7 @@ the ``now()`` is created in the same timezone as the instance.
 
     import pendulum
 
-    dt = Pendulum.now()
+    dt = pendulum.now()
 
     dt.is_weekday()
     dt.is_weekend()
@@ -112,7 +112,7 @@ the ``now()`` is created in the same timezone as the instance.
     dt.is_future()
     dt.is_past()
     dt.is_leap_year()
-    dt.is_same_day(Pendulum.now())
+    dt.is_same_day(pendulum.now())
 
     born = pendulum.create(1987, 4, 23)
     not_birthday = pendulum.create(2014, 9, 26)

docs/_docs/difference.rst

@@ -86,7 +86,7 @@ You may also pass ``True`` as a 2nd parameter to remove the modifiers `ago`, `fr
     pendulum.now().subtract(days=1).diff_for_humans()
     '5 days ago'
 
-    pendulum.now().diff_for_humans(Pendulum.now().subtract(years=1))
+    pendulum.now().diff_for_humans(pendulum.now().subtract(years=1))
     '1 year after'
 
     dt = pendulum.create(2011, 8, 1)