Create the quick start content

This is the main task for creating the quick start content. It includes as following:

• Complete a Basic API Integration
• Create a backend
• Create a product
• Create an application plan
• Create an application
• Create a method
• Create a metric
• Adding mapping rules

if needed, we can create the sub-task for every flow.

Create the content PRs for different flows and maintain the contents.

Resource links:

• https://docs.google.com/document/d/1eDlU51DOgHmImzmALZl9NF3_wHLTIEyqgDsdbzWwfXg/edit