fix the Gitpod automated setup.

Author: nisarhassan12

.gitpod.yml

@@ -1,5 +1,5 @@
 tasks:
-  - init: npm run build
+  - init: npm install && npm run build
     command: npm start
 ports:
   - port: 8000

README.md

@@ -7,6 +7,7 @@
 [![GitHub license](https://img.shields.io/github/license/MrRio/jsPDF.svg)](https://github.com/MrRio/jsPDF/blob/master/LICENSE)
 [![Total alerts](https://img.shields.io/lgtm/alerts/g/MrRio/jsPDF.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/MrRio/jsPDF/alerts/)
 [![Language grade: JavaScript](https://img.shields.io/lgtm/grade/javascript/g/MrRio/jsPDF.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/MrRio/jsPDF/context:javascript)
+[![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod)](https://gitpod.io/from-referrer/)