Added a project

[luciferx1010]

Birthday Letter

In this project a letter will appear and inside that the wishing card is there which will react to hovering event.

Checklist

• I've been assigned an issue related to this PR.
• I've used beautifiers.
• I've added my Project's name and description to Index.md
• I've made a README.md file for my Project.
• The README.md file of my projrct contains Project title, Description, Use of project, Set up, Stack used and Output (Screenshots).

Related Issues or Pull Requests number

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