Adding functions in testing using jest

[japneetsingh035]

This testing function would allow to check if css stylesheet is passed.

test("should be able to pass specified style", () => {
        expect(
            checkGenPageArgsWithCSS(
                data,
                data.texts,
                data.title,
                data.stylesheet,
            ),
        ).argv_s = `<link rel="stylesheet" type="text/css" href="please_add_your_css_path" />`;
    });