`toExpression` doesn't work properly for some operators

[leonid-shutov]

Describe the bug
toExpression doesn't work properly for some operators

To Reproduce

const program = '(eq 1 2)';

const tokens = tokenize(program);

const expression = parse(tokens);

console.log(expression.toExpression()); // (1eq2)

console.log(expression.toJavaScript()); // () => (1eq2)

Expected behavior
expression.toExpression() has to return 1 === 2

Additional context
We probably have to create a mapping between lisp and javascript operators