Replaces the previous name of the working group in Understanding (#4257)

Replace "WCAG" and "Web Content Accessibility Guidelines" with
"Accessibility Guidelines".

---------

Co-authored-by: Mike Gower <[email protected]>
Co-authored-by: Patrick H. Lauke <[email protected]>
Co-authored-by: Mike Gower <[email protected]>
Co-authored-by: Kenneth G. Franqueiro <[email protected]>

Author: 4 people

_includes/understanding/intro/failure.html

@@ -1,3 +1,3 @@
 <p>
-  The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.
+  The following are common mistakes that are considered failures of this Success Criterion by the Accessibility Guidelines Working Group.
 </p>

_includes/understanding/intro/techniques.html

@@ -1,6 +1,6 @@
 <p>
   Each numbered item in this section represents a technique or combination of techniques
-  that the WCAG Working Group deems sufficient for meeting this Success Criterion.
+  that the Accessibility Guidelines Working Group deems sufficient for meeting this Success Criterion.
   A technique may go beyond the minimum requirement of the criterion. There may be other ways of meeting the criterion not covered by these techniques. 
   For information on using other techniques, see
   <a href="understanding-techniques">Understanding Techniques for WCAG Success Criteria</a>,

understanding/20/reading-level.html

@@ -137,7 +137,7 @@ <h3>Levels of education</h3>
          <p>According to the Open Society Mental Health Initiative, the concept of Easy to Read
             cannot be universal, and it will not be possible to write a text that will suit the
             abilities of all people with literacy and comprehension problems. Using the clearest
-            and simplest language appropriate is highly desirable, but the WCAG Working Group
+            and simplest language appropriate is highly desirable, but the Accessibility Guidelines Working Group
             could not find a way to test whether this had been achieved. The use of reading level
             is a way to introduce testability into a success criterion that encourages clear writing.
             Supplementary content can be a powerful technique for people with some classes of

understanding/20/unusual-words.html

@@ -89,7 +89,7 @@ <h2>Resources for Unusual Words</h2>
       <div class="note">
 
          <p>The inclusion of a product or vendor name in the list below does not constitute an
-            endorsement by the Web Content Accessibility Guidelines Working Group or the Web Accessibility
+            endorsement by the Accessibility Guidelines Working Group or the Web Accessibility
             Initiative of the World Wide Web Consortium. This list is provided simply for convenience
             and to give users an idea of what resources may be available
          </p>

understanding/conformance.html

@@ -642,7 +642,7 @@ <h3>Level of Assistive Technology Support Needed for "Accessibility Support"</h3
 
          <p>This topic raises the question of how many or which assistive technologies must support
             a web technology in order for that web technology to be considered "accessibility
-            supported". The WCAG Working group and the W3C do not specify which or how many assistive
+            supported". The Accessibility Guidelines Working Group and the W3C do not specify which or how many assistive
             technologies must support a web technology in order for it to be classified as accessibility
             supported. This is a complex topic and one that varies both by environment and by
             language. There is a need for an external and international dialogue on this topic.
@@ -1039,7 +1039,7 @@ <h3>Techniques for Providing a Conforming Alternate Version</h3>
             <h4>Sufficient Techniques for Providing Conforming Alternative Versions of web pages</h4>
 
             <p>Each numbered item in this section represents a technique or combination of techniques
-               that the WCAG Working Group deems sufficient for meeting this success criterion. However, it is
+               that the Accessibility Guidelines Working Group deems sufficient for meeting this success criterion. However, it is
                not necessary to use these particular techniques. For information on using other techniques,
                see 
                <a href="understanding-techniques"></a>, particularly the "Other Techniques" section.

understanding/understanding-techniques.html

@@ -100,7 +100,7 @@ <h2>Other Techniques</h2>
 			</ul>
 			<section>
 				<h3>Submitting Techniques</h3>
-				<p>The WCAG Working Group encourages people to submit new techniques so that they can be considered for inclusion in updates of the <a href="../Techniques/">Techniques for WCAG {{ versionDecimal }}</a> document. Please submit techniques for consideration to the <a href="https://github.com/w3c/wcag/">WCAG repository on GitHub</a>.</p>
+				<p>The Accessibility Guidelines Working Group encourages people to submit new techniques so that they can be considered for inclusion in updates of the <a href="../Techniques/">Techniques for WCAG {{ versionDecimal }}</a> document. Please submit techniques for consideration to the <a href="https://github.com/w3c/wcag/">WCAG repository on GitHub</a>.</p>
 			</section>
 		</section>
 		<section>