make an abstraction for serving the html files

[Karyum]

so about 40 lines here are using the same functionality with a slight difference in the filenames, we could improve that by making 1 function that handles all the cases

example

// router.js

if (Url === '/User') {
 serveHtml(request,response, 'user')


// the third argument is the html file name so in the serveHtml function 
// you can do something like this
const filepath = path.join(__dirname, '..', 'public', `${name}.html`);

}