I do a lot of HTML generation just with JavaScript and am finding myself creating `index.html` files that have code that looks like this:

     <!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>

It would be nice to be able to do:

     browserWindow.loadHTML('<!DOCTYPE html><html><head><script src="index.js"></script></head><body></body></html>');

It would be even more awesome to do:

     browserWindow.loadScript(pathToScript);

I tried to use the `preload` option for `BrowserWindow` and using `loadURL('about:blank')`, but this has an unintended side effect of not allowing you to reference other script or CSS files using relative paths.

What do you think about proposed feature?
atom/browser/api/atom_api_web_contents.cc
content::NavigationHandle* navigation_handle) {
  if (!navigation_handle->IsInMainFrame() || navigation_handle->IsSamePage())
    return;
  if (deferred_load_url_.id) {
    auto web_contents = navigation_handle->GetWebContents();
    auto& controller = web_contents->GetController();
    int id = controller.GetPendingEntry()->GetUniqueID();
    if (id == deferred_load_url_.id) {
      if (!deferred_load_url_.params.url.is_empty()) {
        auto params = deferred_load_url_.params;
        deferred_load_url_.id = 0;
        deferred_load_url_.params =
            content::NavigationController::LoadURLParams(GURL());
        controller.LoadURLWithParams(params);
        SetBackgroundColor(web_contents);
      } else {
        deferred_load_url_.id = 0;
      }
    }
  }
}
void WebContents::DidFinishNavigation(