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!