Fix README typo and improve installation example

Describe the issue

The README contains minor typos and is missing a concise "Quick start" installation example, which can help new users onboard faster.

To do

• Fix obvious typos in README.md
• Add a "Quick start" code block with minimal commands to install and run WilderedOS (or placeholder commands if instructions are simple)
• Review the README for clarity

Acceptance criteria

• README.md does not have the listed typos
• "Quick start" code example is present and correct
• The section is easy to locate at the top of the file
• CI checks (if any) pass

Notes

This is a good first issue for anyone wanting to get familiar—edit a markdown file and propose a PR!