Update reference from WCAG 2.1 to WCAG 2.2 (#489)

index.html

@@ -78,7 +78,7 @@ <h1>Introduction</h1>
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             <p>While this specification defines a unified event model for a variety of pointer inputs, this model does not cover other forms of input such as keyboards or keyboard-like interfaces (for instance, a screen reader or similar assistive technology running on a touchscreen-only device, which allows users sequential navigation through focusable controls and elements). While user agents might choose to also generate pointer events in response to these interfaces, this scenario is not covered in this specification.</p>
 
-            <p>In the first instance, authors are encouraged to provide equivalent functionality for all forms of input by responding to high-level events such as <code>focus</code>, <code>blur</code> and <code>click</code>. However, when using low-level events (such as Pointer Events), authors are encouraged to ensure that all types of input are supported. In the case of keyboards and keyboard-like interfaces, this might require the addition of explicit keyboard event handling. See <a href="https://www.w3.org/TR/WCAG/#keyboard-accessible"><cite><abbr title="Web Content Accessibility Guidelines">WCAG</abbr> Guideline 2.1 Keyboard Accessible</cite></a> [[WCAG21]] for further details.</p>
+            <p>In the first instance, authors are encouraged to provide equivalent functionality for all forms of input by responding to high-level events such as <code>focus</code>, <code>blur</code> and <code>click</code>. However, when using low-level events (such as Pointer Events), authors are encouraged to ensure that all types of input are supported. In the case of keyboards and keyboard-like interfaces, this might require the addition of explicit keyboard event handling. See <a href="https://www.w3.org/TR/WCAG/#keyboard-accessible"><cite><abbr title="Web Content Accessibility Guidelines">WCAG</abbr> Guideline 2.1 Keyboard Accessible</cite></a> [[WCAG22]] for further details.</p>
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