Own Package with a custom HTML Page



i want to make a package with some custom HTML as a new Tab. Somting like opening a new file and with a key combination split the editor for my html code that uses the data in the file. Like a todo app which uses a file for the data and a new tab as the display.

How do i make this? i am not very skilled in making Atom packages… only in html, js and css. is there a blueprind in which i only need to write my html/css/js like a normal Webpage?