problem with `custom` documentation

https://package.elm-lang.org/packages/MacCASOutreach/graphicsvg/latest/GraphicSVG#custom

In block comment:
```
custom [ ( 10, 5 ) ] 5 -- a line with dashes 10 long and spaces 5 long

custom [ ( 10, 5 ), ( 20, 5 ) ] -- on for 10, off 5, on 20, off 5
```

Second line needs a thickness.