[css-anchor-position] Remove lingering referenced to the 'implicit' keyword. w3c#10312

Author: tabatkins

css-anchor-position-1/Overview.bs

@@ -197,8 +197,8 @@ for a given positioned element.
 	which sets the implicit anchor element.
 
 [=Implicit anchor elements=] can be referenced
-with the ''implicit'' keyword,
-rather than referring to some 'anchor-name' value.
+with the ''auto'' keyword in 'position-anchor',
+or by omitting the anchor reference in [=anchor functions=].
 
 [=Pseudo-elements=]
 have the same [=implicit anchor element=]
@@ -324,7 +324,7 @@ given an <dfn>anchor specifier</dfn>,
 which is either a <<dashed-ident>>
 (and a [=tree-scoped reference=])
 that should match an 'anchor-name' value elsewhere on the page,
-or the keyword ''implicit'',
+or the keyword ''auto'',
 or nothing (a missing specifier).
 
 Note: The general rule captured by these conditions
@@ -351,7 +351,7 @@ in anchor positioning.
 		for |query el|
 		given the |query el|'s [=default anchor specifier=].
 
-	2. If |anchor spec| is ''implicit'':
+	2. If |anchor spec| is ''auto'':
 		1. If the Popover API defines an [=implicit anchor element=] for |query el|
 			which is an [=acceptable anchor element=] for |query el|,
 			return that element.