Editing Build Command

[paynito]

tools: System: New Build System

gives the template 
{
	"shell_cmd": "make"
}

I currently compile my latex file with

latexmk -xelatex -f main.tex

I don’t understand how to put this into the template.
Do I replace it all with

{ "shell_cmd": "latexmk",
            "-e", "\\$pdflatex = 'xelatex %O -interaction=nonstopmode -synctex=1 %S'",
            "-f", "-pdf"],
            "name": "myXeLaTeX"
            }

and then save? Sublime Text throws the error: No Build System.