Reference for Basic Shapes: code example fix for screen readers

[git-ebetts]

Nature of issue?

• [ ] Found a bug
• [x] Existing feature enhancement
• [ ] New feature request

Details about the bug:

• Web browser and version:
• Operating System:
• Steps to reproduce this:

Feature enhancement details:

When using a screen reader, the code examples on the Basic Shapes reference pages present the actual code before a brief description of what the code example accomplishes. I propose reversing this order so that screen reader users reviewing code examples will first hear a description of what is rendered followed by the required code.