I tried your code above and it worked fine on an http-server, but did not work in a jsFiddle. It might be your development environment or browser. Even double-clicking the .html file pulled it up in chrome, correctly displaying the SVG:
<svg width="1024" height="1024"><g class="venn-area venn-circle" data-venn-sets="0"><path d="
M 807.1589756762538 512
m -201.8410243237462 0
a 201.8410243237462 201.8410243237462 0 1 0 403.6820486474924 0
a 201.8410243237462 201.8410243237462 0 1 0 -403.6820486474924 0" style="fill-opacity: 0.25; fill: rgb(31, 119, 180);"></path><text class="label" text-anchor="middle" dy=".35em" x="876" y="511" style="fill: rgb(31, 119, 180);"><tspan x="876" y="511" dy="0.35em">0 X</tspan></text></g><g class="venn-area venn-circle" data-venn-sets="1"><path d="
M 215.93473308618636 512
m -200.93473308618638 0
a 200.93473308618638 200.93473308618638 0 1 0 401.86946617237277 0
a 200.93473308618638 200.93473308618638 0 1 0 -401.86946617237277 0" style="fill-opacity: 0.25; fill: rgb(255, 127, 14);"></path><text class="label" text-anchor="middle" dy=".35em" x="148" y="511" style="fill: rgb(255, 127, 14);"><tspan x="148" y="511" dy="0.35em">1 X</tspan></text></g><g class="venn-area venn-circle" data-venn-sets="2"><path d="
M 512.8582181751124 512
m -230.42479022003167 0
a 230.42479022003167 230.42479022003167 0 1 0 460.84958044006333 0
a 230.42479022003167 230.42479022003167 0 1 0 -460.84958044006333 0" style="fill-opacity: 0.25; fill: rgb(44, 160, 44);"></path><text class="label" text-anchor="middle" dy=".35em" x="511" y="397" style="fill: rgb(44, 160, 44);"><tspan x="511" y="397" dy="0.35em">2 X</tspan></text></g><g class="venn-area venn-intersection" data-venn-sets="0_2"><path d="
M 681.000362208242 669.5557150594287
A 201.8410243237462 201.8410243237462 0 0 1 681.000362208242 354.44428494057126
A 230.42479022003167 230.42479022003167 0 0 1 681.000362208242 669.5557150594287" style="fill-opacity: 0;"></path><text class="label" text-anchor="middle" dy=".35em" x="674" y="512" style="fill: rgb(68, 68, 68);"><tspan x="674" y="512" dy="0.35em"></tspan></text></g><g class="venn-area venn-intersection" data-venn-sets="1_2"><path d="
M 342.9754402017427 667.6773127208855
A 230.42479022003167 230.42479022003167 0 0 1 342.9754402017427 356.32268727911446
A 200.93473308618638 200.93473308618638 0 0 1 342.9754402017427 667.6773127208855" style="fill-opacity: 0;"></path><text class="label" text-anchor="middle" dy=".35em" x="349" y="512" style="fill: rgb(68, 68, 68);"><tspan x="349" y="512" dy="0.35em"></tspan></text></g><g class="venn-area venn-intersection" data-venn-sets="0_1_2"><path d="M 0 0" style="fill-opacity: 0;"></path><text class="label" text-anchor="middle" dy=".35em" x="0" y="-1000" style="fill: rgb(68, 68, 68);"><tspan x="0" y="-1000" dy="0.35em"></tspan></text></g></svg>
I used this exact library in production a few years back - it was tricky. The key is to look carefully at the size: numbers. We ran into data with enough relationships that (in some cases) it was impossible to render a venn. It will quietly error and not render all relationships. So we put in a polyfill that would re-render (multiple-sets) until all relationships were shown.
Are you just seeing a white screen? One thing I would do is to download the two .js files and reference them locally. That might do the trick. Check your console log for errors. Chrome DevTools may help. Also, the server I use is http-server from npm. Just type in http-server in any directory and then the path to your .html and it will be there on http://localhost:8080/path/to/your/venn.html.
Hope that helps.