Update Navigation plugin docs for useAriaCurrentAttr

[johnhunter]

Add docs for 11ty/eleventy-navigation#43 released in v1.0.0

[aloxe]

Suggested change

	You can also add an `aria-current="page"` attribute (see [more details here](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-current))
	You can also add the `aria-current="page"` attribute on links to the current page (see [more details here](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-current))

[cypressSap]

useAriaCurrentAttr defaults to false, and is only added if activeKey is matched, so I'd further update the navigationOptions examples:

{
  navigationOptions: {
    listElement: "ul",            // Change the top level tag
    listItemElement: "li",        // Change the item tag

    listClass: "",                // Add a class to the top level
    listItemClass: "",            // Add a class to every item
    listItemHasChildrenClass: "", // Add a class if the item has children
    activeListItemClass: "",      // Add a class to the current page’s item

    anchorClass: "",              // Add a class to the anchor
    activeAnchorClass: "",        // Add a class to the current page’s anchor

    useAriaCurrentAttr: false,      // Add aria-current="page" to the current page’s anchor

    // If matched, `activeListItemClass`, `activeAnchorClass`, and `useAriaCurrentAttr` will be added
    activeKey: "",
    // It’s likely you want to pass in `eleventyNavigation.key` here, e.g.:
    // activeKey: eleventyNavigation.key

    // Show excerpts (if they exist in data, read more above)
    showExcerpt: false
  }
}

[Ryuno-Ki]

Why was the whitespace removed here? I felt it helped the readability.