User sentence case for headers

Author: mikehang-msft

articles/communication-services/quickstarts/rooms/manage-rooms-call.md

@@ -67,7 +67,7 @@ call_connection_properties = client.connect_call(call_locator=room_call_locator,
 Once successfully connected to a room call, a `CallConnect` event is notified via Callback URI. You can use `callConnectionId` to retrieve a call connection on the room call as needed. The following sample code snippets use the `callConnectionId` to demonstrate this function.
 
 
-### Add PSTN Participant
+### Add PSTN participant
 Using Call Automation you can dial out to a PSTN number and add the participant into a room call. You must, however, set up a room to enable PSTN dial-out option (`EnabledPSTNDialout` set to `true`) and the Azure Communication Services resource must have a valid phone number provisioned.
 
 For more information, see [Rooms quickstart](../../quickstarts//rooms/get-started-rooms.md?tabs=windows&pivots=platform-azcli#enable-pstn-dial-out-capability-for-a-room).
@@ -120,7 +120,7 @@ result = call_connection_client.add_participant(
 ```
 -----
 
-### Remove PSTN Participant
+### Remove PSTN participant
 
 ### [csharp](#tab/csharp)
 
@@ -218,7 +218,7 @@ result = call_connection_client.send_dtmf_tones(
 ```
 -----
 
-### Call Recording
+### Call recording
 Azure Communication Services rooms support recording capabilities including `start`, `stop`, `pause`, `resume`, and so on, provided by Call Automation. See the following code snippets to start/stop/pause/resume a recording in a room call. For a complete list of actions, see [Call Automation recording](../../concepts/voice-video-calling/call-recording.md#get-full-control-over-your-recordings-with-our-call-recording-apis).
 
 ### [csharp](#tab/csharp)
@@ -315,7 +315,7 @@ stop_recording = call_automation_client.stop_recording(recording_id = recording_
 ```
 -----
 
-### Terminate a Call
+### Terminate a call
 You can use the Call Automation SDK Hang Up action to terminate a call. When the Hang Up action completes, the SDK publishes a `CallDisconnected` event.
 
 ### [csharp](#tab/csharp)
@@ -347,7 +347,7 @@ call_connection_client.hang_up(is_for_everyone=True)
 ```
 -----
 
-## Other Actions
+## Other actions
 The following in-call actions are also supported in a room call. 
 1. Add participant (ACS identifier)
 1. Remove participant (ACS identifier)