title: Make d3 graphviz graph fit screen but not scale svg
body: <p>I've made use of the basic <a href="https://github.com/magjac/d3-graphviz/blob/master/examples/basic-zoom-fit-window.html" rel="nofollow noreferrer">zoom to fit window example in d3-graphviz</a></p>
  
  <p>Which is great, however, I'd like to make it so that the svg doesn't automatically fill the whole screen. And doesn't effectively change the zoom when the svg increases.</p>
  
  <p>If I transition the graph to have an extra node, it appears to zoom out (because the SVG has been made to fill the page) </p>
  
  <p>If zoom is turned off then each node is a set size which is great (regardless of if the graph has 1 or 100 nodes).</p>
  
  <p>I'd like to make it so that a new render will by default have a node of that original size. And if a transition involves adding new nodes or edges (thus increasing the size) the zoom is maintained. </p>
  
  <p>edit: I guess I want to keep zoom enabled, the graph size to be equal to the window size, but not scale the svg itself although I may have that back to front</p>