Add installation, contributing instructions to readme

[wigiwee]

Important
This pull request addresses an issue with the README.md file of the YoutubeDownload repository, which lacked installation instructions. This omission led to confusion and wasted time for users trying to install and use the application. It took me 20 min to get this running locally

Summary of Changes:

• Added clear and detailed installation instructions to the README.md file.
• Included steps for setting up and running the application.
• Ensured that the new instructions align with the project's existing format and style.

Why This Change Is Necessary:
The absence of installation instructions in the README.md made it challenging for users to get started with the project. By providing a well-documented guide, this update aims to improve the user experience and reduce onboarding time for new users.

[Tyrrrz]

This omission led to confusion and wasted time for users trying to install and use the application. It took me 20 min to get this running locally

Did you struggle with specifically building it locally or running the downloaded version locally?

If the former, it's better to put these instructiosn into a Contributing.md file.

[Copilot]

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[wigiwee]

Did you struggle with specifically building it locally or running the downloaded version locally?

running downloaded version locally