[css-anchor-position] Add Changes section

Author: tabatkins

css-anchor-position-1/Overview.bs

@@ -686,7 +686,7 @@ In order (and using the [=writing mode=] of the [=containing block=]):
 	or the end edge of the [=default anchor box=]
 	if that is more [=end=]-ward.
 
-An <<position-area>> selects a region of this grid
+A <<position-area>> selects a region of this grid
 by specifying the rows and columns the region occupies,
 with each of the two keywords specifying one of them:
 
@@ -2400,3 +2400,25 @@ Privacy Considerations {#priv}
 
 No Privacy issues have been raised against this document.
 
+Changes {#changes}
+=======
+
+Significant changes since the <a href="https://www.w3.org/TR/2024/WD-css-anchor-position-1-20240326/">26 March 2024 Working Draft</a>:
+
+* Renamed <css>inset-area</css> to 'position-area'
+* Added ''position-anchor: auto''
+	to use the [=implicit anchor element=] as the [=default anchor element=]
+* Added top-layer details to the [=acceptable anchor element=] definition
+* Removed the <css>implicit</css> keyword from the [=anchor functions=]
+	(omitting an anchor name does the same thing)
+* Removed the "reduce the size of the available space" behavior from ''anchor-center'',
+	now that Align defines how to shift to avoid overflow.
+* Added 'position-visibility', to hide the positioned element in some cases.
+* Added a11y guidance ([[#accessibility]])
+* Expanded the set of properties that ''anchor-size()'' is used in
+	(to all the relevant [=accepted @position-try properties=]).
+* Renamed <css>position-try-options</css> to 'position-try-fallbacks'
+* Removed the <css>inset-area()</css> function from 'position-try-fallbacks'
+	(you just use a 'position-area' value directly now).
+* Defined how to [=swap due to a try tactic=].
+* Expanded the details of how to [=determine position fallback styles=].