Add TS declaration file for SegmentEmitter (#586)

Author: carolabadeer

packages/core/lib/segment_emitter.d.ts

@@ -0,0 +1,13 @@
+import Segment = require('./segments/segment');
+
+export function format(segment: Segment): string;
+
+export function send(segment: Segment): void;
+
+export function setDaemonAddress(address: string): void;
+
+export function getIp(): string;
+
+export function getPort(): number;
+
+export function disableReusableSocket(): void;

packages/core/lib/segment_emitter.js

@@ -106,6 +106,7 @@ var SegmentEmitter = {
 
   /**
    * Returns the formatted segment JSON string.
+   * @param {Segment} segment - The segment to format.
    */
 
   format: function format(segment) {