Minor fix: change "User Agent" to "user agent"

Author: patrickhlauke

mediaqueries/Overview.bs

@@ -1600,15 +1600,15 @@ Interaction Media Features</h2>
 	The 'pointer' and 'hover' features relate to the characteristics of the “primary” pointing device, 
 	while 'any-pointer' and 'any-hover' can be used to query the properties of all potentially available pointing devices.
 
-	Note: While this specification does not define how User Agents should decide what the “primary” pointing device is, 
-	the expectation is that User Agents should make this determination 
+	Note: While this specification does not define how user agents should decide what the “primary” pointing device is, 
+	the expectation is that user agents should make this determination 
 	by combining knowledge about the device/environment they are running on, 
 	the number and type of pointing devices available, 
 	and a notion of which of these is generally and/or currently being used.
 	In situations where the primary input mechanism for a device is not a pointing device,
 	but there is a secondary – and less frequently used – input that is a pointing devices,
 	the user agent may decide to treat the non-pointing device as the primary (resulting in 'pointer: none').
-	User Agents may also decide to dynamically change what type of pointing device is deemed to be primary, 
+	user agents may also decide to dynamically change what type of pointing device is deemed to be primary, 
 	in response to changes in the user environment 
 	or in the way the user is interacting with the UA.