Add Proper Documentation, Links and Subgraphs Mermaid Diagram to the Readme File

[deepak-likes-code]

Suggested Improvements to the current repo readme.md file

• Add the description of the projects and the steps required to reproduce it and use it
• Add the associated links and the contract addresses used for the graph protocol
• Add the link of the subgraph that is deployed
• Add a mermaid diagram representing the subgraph's schema. For more information about mermaid files checkout https://mermaid-js.github.io/mermaid/