When I first started out I was using free web hosts that didn't support server-side includes or PHP, so I ended up building my own JavaScript front end framewor

When I first started out I was using free web hosts that didn't support server-side includes or PHP, so I ended up building my own JavaScript front end framework. Unfortunately, I didn't actually know any JavaScript, so I wrapped every line of my HTML header template in document.write() and included it in a script tag. There were some performance issues.