Added documentation

[Yarlin16]

Describe your changes (Mandatory)

I have added documentation to Memory game and also included it into the main website.

Screenshots of your project, whatever you have added. (Mandatory)

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [x] If it is a new project, I have done thorough tests.
• [x] Have you updated the README file of the repository and added the name of the project in it?
• [x] Have you added a README.md file inside the directory of your project and explained it there properly (with images)?
• [x] Have you updated the script.js file so that the project is visible in the website?

[Yarlin16]

@shrey141102 Although I have signed off my commit, yet it is showing that the DCO check has failed. Is there anything else I should do to avoid that error?

[shrey141102]

@shrey141102 Although I have signed off my commit, yet it is showing that the DCO check has failed. Is there anything else I should do to avoid that error?

let it be for now, I have passed it