Some improvements to README.md

[joewiz]

• Correct errors (remove semi-colons, add ns decl) (I tested the code in eXide and confirmed it works)
• Add the expected output

Please squash and merge, as the GitHub web interface mangled my initial commit.

[joewiz]

@ljo Would you consider merging this in? It corrects errors in the README.md.

[joewiz]

I'll also be happy to test if these changes are still valid or not.

[mathias-goebel]

👍

[joewiz]

@ljo I'd be grateful if you would merge this.