chore: formatting code to match our other doc's styles

src/content/docs/apis/rest-api-v2/browser-examples-v2/average-browser-end-user-page-throughput-example-v2.mdx

@@ -16,10 +16,10 @@ The average browser throughput appears at the top right of the <DNT>**Throughput
 
 ## Average page throughput [#h2-average]
 
-To obtain the [average](/docs/apm/apis/requirements/calculating-average-metric-values-summarize) for the [time range](/docs/apm/apis/requirements/specifying-time-range-api-v2) (default is last 30 minutes), use the following command. Be sure to replace the `${APP_ID}` and `${API_KEY}` variables in this example with your specific [application ID](/docs/apm/apis/requirements/identification-code) and [REST API key](/docs/apis/rest-api-v2/requirements/rest-api-key#viewing).
+To obtain the [average](/docs/apm/apis/requirements/calculating-average-metric-values-summarize) for the [time range](/docs/apm/apis/requirements/specifying-time-range-api-v2) (default is last 30 minutes), use the following command. Be sure to replace the `$APP_ID` and `$API_KEY` variables in this example with your specific [application ID](/docs/apm/apis/requirements/identification-code) and [REST API key](/docs/apis/rest-api-v2/requirements/rest-api-key#viewing).
 
-```
-curl -X GET "https://api.newrelic.com/v2/applications/${APP_ID}/metrics/data.json" \
-     -H "X-Api-Key:${API_KEY}" -i \
+```sh
+curl -X GET "https://api.newrelic.com/v2/applications/$APP_ID/metrics/data.json" \
+     -H "X-Api-Key:$API_KEY" -i \
      -d 'names[]=EndUser&values[]=requests_per_minute&summarize=true'
 ```