Adding Attributes + Values to a particular tag


Hi Guys,

Very new to Atom and wondering if anyone can point me in the right direction on how I can create my own attributes and values within a specific HTML tag please?

For example;
I created a snippet package that works with HTML files and one of them is below. I hit TAB to jump to a focus point in the tag and then autocomplete suggests certain values that I can choice from. So ForceProvider will have 2 values to select from DnnPageHeaderProvider or DnnFormBottomProvider. I select one from the dropdown suggestions and it moves to the next focus point PathNameAlias

<dnn:DnnJsInclude runat=“server” Priority="1" **ForceProvider**="{2:DnnPageHeaderProvider|DnnFormBottomProvider}" PathNameAlias="${3:SkinPath|SharedScripts}" FilePath="$4" />

Hope this makes sense and any help will be greatly appreciated. Thank-you