Improvement🎨 to GKE Guide

[smaranjitghose]

Improve the presentation of content on the Google Kubernetes Engine Guide to deploy the app.

• Add images(snapshots) of the process
• Add GIFs
• Make a banner to replace the heading of the markdown file
• Add a section called Tips and address possible ways to fix errors. Don't forget to cite the references. Example
• Update any instruction if required
• Please put the associated images inside Guides/assets/