chore: add script and update readme

Author: mayurkale22

examples/basic-tracer-node/README.md

@@ -57,6 +57,17 @@ Click on the trace to view its details.
 
 <p align="center"><img src="./images/jaeger-ui-detail.png?raw=true"/></p>
 
+### Export to multiple exporters
+
+ - Run the sample
+
+   ```sh
+   $ # from this directory
+   $ npm run multi_exporter
+   ```
+
+   This will export the spans data simultaneously on `Zipkin` and `Jaeger` backend. This is handy if transitioning from one vendor/OSS project to another for the tracing backend. You might want to export to both during the transitional phase.
+
 ## Useful links
 - For more information on OpenTelemetry, visit: <https://opentelemetry.io/>
 - For more information on tracing, visit: <https://github.com/open-telemetry/opentelemetry-js/tree/master/packages/opentelemetry-tracing>

examples/basic-tracer-node/package.json

@@ -6,7 +6,8 @@
   "main": "index.js",
   "scripts": {
     "zipkin:basic": "cross-env EXPORTER=zipkin node ./index.js",
-    "jaeger:basic": "cross-env EXPORTER=jaeger node ./index.js"
+    "jaeger:basic": "cross-env EXPORTER=jaeger node ./index.js",
+    "multi_exporter": "node ./multi_exporter.js"
   },
   "repository": {
     "type": "git",