Help users make SVG and HTML content which scales appropriately

[casey]

Often, HTML and SVG inscriptions don't scale correctly when viewed at different sizes. Here's an example where only the corner of the image is visible.

We should help users make SVGs and HTML that are size independent, and so correctly resize when displayed at any size. Some ideas:

• Simple HTML and SVG examples that show how to do this
• Examples of what to avoid
• A section in the guide that mentions this