chore(api): add sync startSegment example

examples/api/segments/example4-sync-assign.js

@@ -0,0 +1,22 @@
+'use strict'
+
+var newrelic = require('newrelic')
+
+// Segments can only be created inside of transactions. They could be automatically
+// generated HTTP transactions or custom transactions.
+newrelic.startBackgroundTransaction('bg-tx', function transHandler() {
+  // `startSegment()` takes a segment name, a boolean if a metric should be
+  // created for this segment, the handler function, and an optional callback.
+  // The handler is the function that will be wrapped with the new segment.
+
+  var output = newrelic.startSegment('myCustomSegment', false, function timedFunction() {
+    return someSyncTask()
+  })
+  console.log(output)
+})
+
+function someSyncTask() {
+  var result = mySyncTask()
+  var output = myNextTask(result)
+  return output
+}