Use Note in SyclTimer docstring

Also fix grammar in the text of the note.

Author: oleksandr-pavlyk

dpctl/_sycl_timer.py

@@ -69,14 +69,14 @@ class SyclTimer:
             # retrieve elapsed times in milliseconds
             wall_dt, device_dt = timer.dt
 
-    Remark:
+    Note:
         The timer submits barriers to the queue at the entrance and the
         exit of the context and uses profiling information from events
         associated with these submissions to perform the timing. Thus
         :class:`dpctl.SyclTimer` requires the queue with "enable_profiling"
         property. In order to be able to collect the profiling information
-        the property `dt` ensures that both submitted barriers complete
-        their execution and thus effectively synchronizing the queue.
+        the property, the `dt` method ensures that both submitted barriers
+        complete their execution and thus effectively synchronizes the queue.
 
     Args:
         host_timer (callable): A callable such that host_timer() returns current