Simplify TS code snippets on phone quickstart (#632)

* chore(quickstart/phone): simplify code snippets

* fix: replace `voice_id` with `voiceId` in examples

Author: goosewin

fern/assistants/examples/docs-agent.mdx

@@ -137,7 +137,7 @@ Guidelines:
             // Configure voice settings
             voice={
                 "provider": "vapi",
-                "voice_id": "Harry"
+                "voiceId": "Harry"
             },
             // Configure transcription
             transcriber={
@@ -274,7 +274,7 @@ Guidelines:
           // Configure voice settings
           voice: {
             provider: "vapi",
-            voice_id: "Harry"
+            voiceId: "Harry"
           },
           // Configure transcription
           transcriber: {
@@ -341,7 +341,7 @@ Guidelines:
             // Configure voice settings
             voice={
                 "provider": "vapi",
-                "voice_id": "Harry"
+                "voiceId": "Harry"
             },
             // Configure transcription
             transcriber={

fern/assistants/examples/inbound-support.mdx

@@ -159,7 +159,7 @@ We will be creating a customer support agent for VapiBank, a bank that wants to
       },
       voice: {
         provider: "11labs",
-        voice_id: "burt"
+        voiceId: "burt"
       }
     });
 
@@ -193,7 +193,7 @@ We will be creating a customer support agent for VapiBank, a bank that wants to
         },
         "voice": {
             "provider": "11labs",
-            "voice_id": "burt"
+            "voiceId": "burt"
         }
     }
 
@@ -222,7 +222,7 @@ We will be creating a customer support agent for VapiBank, a bank that wants to
            },
            "voice": {
              "provider": "11labs",
-             "voice_id": "burt"
+             "voiceId": "burt"
            }
          }'
     ```

fern/assistants/examples/voice-widget.mdx

@@ -382,7 +382,7 @@ const EcommerceSupportWidget = () => {
         greeting: 'Hi! Need help with your order?',
         voice: {
           provider: 'playht',
-          voice_id: 'jennifer',
+          voiceId: 'jennifer',
         },
       }}
     />
@@ -403,7 +403,7 @@ const HealthcareWidget = () => {
         greeting: 'Hello! I can help schedule your appointment.',
         voice: {
           provider: 'playht',
-          voice_id: 'jennifer',
+          voiceId: 'jennifer',
         },
       }}
     />