docs: add start instructions for Windows and Linux to README

[Sleeping-Simi]

Fixes #4640

Tasks

• Reviewed contribution guidelines
• [x ] PR is descriptively titled 📑 and links the original issue above 🔗
• Tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR
  Run tests locally to check for errors.
• [x ] Commits are in uniquely-named feature branch and has no merge conflicts 📁
• [x ] Updated documentation pages (if applicable)
• Updated CHANGELOG.rst (if applicable)

Signed-off-by: Sovangi Poddar sovangipoddar@gmail.com