What you are seeing there is the placeholder for the item results within a Control Template, so by editing this HTML file you can affect the wrapper around the results (for example to style or apply paging or other static elements to the page) but not the results.
In either of the search results web parts (Search or Content Search) you have the option of applying two templates, a Control and Item. The Item is the one you are looking for if you want to style the results.
What you need to do is locate the item template being used, copy it in the location it sits (Masterpage Gallery under Display Templates) and paste it back, rename it and open the file in something like Notepad++. Change the title of the HTML document (that's what you will see in the web part drop downs later) and then change the DIV contents to show what you need for each result and save back the file to the folder to allow SharePoint to generate the .JS file automatically for you.
After that you can open the Web Part settings and choose your new template. Once you publish the page you can keep editing the HTML (map the location as a drive works well) and see the changes you make to the HTML as you save (allowing a few seconds for the .JS to be auto generated each time).
Hope this helps.