Include more detail in purpose section on README

[rak3rman]

It may be hard for new contributors to understand what Shafa is all about. Include more details under the Purpose section on the README about what Shafa is and what it does on a high level (beyond the original principles).

Acceptance Criteria

Generated by Zenhub AI

• [ ] Scenario: Purpose section on README
  • Given the README file exists and contains a "Purpose" section
  • When the "Purpose" section is updated with more details about Shafa
  • Then new contributors can easily understand what Shafa is and what it does on a high level
  • And the updated "Purpose" section should be concise and clear
  • And the original principles should still be mentioned in the "Purpose" section