title: Drawing a grid using SVG markup
body: <p>I'm seeking to draw a grid onto which i will be adding a number of simple rectangles, again using SVG. The grid should fit on a single page when viewed in a browser. Suspect i'm missing something very simple but do i code the SVG (viewport and grid) for this outcome; namely a grid? 
  I've read advice to specify a viewbox that defines the internal coordinate system of the document's canvas; also that it's possible to set height and width attributes as percentages (?). Ideally final result (ultimately a map) is to have gridlines.  </p>