We should have a template for a new API development. Referencing from the #335 and #65

The template must include:

Overview

• Description of the API
• Who should be involved in the development
• Expected outcome of the API
• User guide

Low-level design

• API specification
• Pallet development + unit testing + benchmarking
• Pop API library + integration tests
  • New traits? New function selector?
  • New errors?
• Example contract + testing with pop-drink