message: Add subfile and includegraphics to snippet commands
diff: "command":"include",
  "snippet":"include{$1}",
  "postAction":"editor.action.triggerSuggest"
  + },
  + "subfile":{
  + "command":"subfileincludegraphics",
  + "snippet":"subfile{$1}",
  + "postAction":"editor.action.triggerSuggest"
  + },
  + "includegraphics":{
  + "command":"includegraphics",
  + "snippet":"includegraphics{$1}",
  + "postAction":"editor.action.triggerSuggest"
  }
  }
  