Bug: Currently active menu item is not conveyed programmatically in the header

[andrewhick]

When documentation includes links in the header, for example on the WCAG Primer page, the currently active menu item, such as Overview or All Requirements, is conveyed visually (by changing the text from white to blue) but not programmatically.

While it meets WCAG 1.4.1 Use of Colour (because the contrast ratio between white and blue is at least 3:1) it fails WCAG 1.3.1 Info and Relationships because information is not conveyed programmatically - for example by using aria-current.

This was originally raised as WCAG Primer issue 132.