[css-anchor-position-2] Rename x/y-self-start/end to self-x/y-start/end #12749 (#12912)

Author: lilles

css-anchor-position-2/Overview.bs

@@ -233,12 +233,12 @@ with an additional ''any'' keyword added to every production:
 <dfn>&lt;position-area-query></dfn> = [
 	[ left | center | right | span-left | span-right
 	| x-start | x-end | span-x-start | span-x-end
-	| x-self-start | x-self-end | span-x-self-start | span-x-self-end
+	| self-x-start | self-x-end | span-self-x-start | span-self-x-end
 	| span-all | any ]
 	||
 	[ top | center | bottom | span-top | span-bottom
 	| y-start | y-end | span-y-start | span-y-end
-	| y-self-start | y-self-end | span-y-self-start | span-y-self-end
+	| self-y-start | self-y-end | span-self-y-start | span-self-y-end
 	| span-all | any ]
 |
 	[ block-start | center | block-end | span-block-start | span-block-end | span-all | any ]
@@ -267,15 +267,15 @@ with an additional ''any'' keyword added to every production:
 
 	: <dfn>start</dfn>, <dfn>end</dfn>, <dfn>self-start</dfn>, <dfn>self-end</dfn>
 	: <dfn>top</dfn>, <dfn>bottom</dfn>, <dfn>left</dfn>, <dfn>right</dfn>
-	: <dfn>y-start</dfn>, <dfn>y-end</dfn>, <dfn>y-self-start</dfn>, <dfn>y-self-end</dfn>
-	: <dfn>x-start</dfn>, <dfn>x-end</dfn>, <dfn>x-self-start</dfn>, <dfn>x-self-end</dfn>
+	: <dfn>y-start</dfn>, <dfn>y-end</dfn>, <dfn>self-y-start</dfn>, <dfn>self-y-end</dfn>
+	: <dfn>x-start</dfn>, <dfn>x-end</dfn>, <dfn>self-x-start</dfn>, <dfn>self-x-end</dfn>
 	: <dfn>block-start</dfn>, <dfn>block-end</dfn>, <dfn>self-block-start</dfn>, <dfn>self-block-end</dfn>
 	: <dfn>inline-start</dfn>, <dfn>inline-end</dfn>, <dfn>self-inline-start</dfn>, <dfn>self-inline-end</dfn>
 	: <dfn>center</dfn>
 	: <dfn>span-start</dfn>, <dfn>span-end</dfn>, <dfn>span-self-start</dfn>, <dfn>span-self-end</dfn>
 	: <dfn>span-top</dfn>, <dfn>span-bottom</dfn>, <dfn>span-left</dfn>, <dfn>span-right</dfn>
-	: <dfn>span-y-start</dfn>, <dfn>span-y-end</dfn>, <dfn>span-y-self-start</dfn>, <dfn>span-y-self-end</dfn>
-	: <dfn>span-x-start</dfn>, <dfn>span-x-end</dfn>, <dfn>span-x-self-start</dfn>, <dfn>span-x-self-end</dfn>
+	: <dfn>span-y-start</dfn>, <dfn>span-y-end</dfn>, <dfn>span-self-y-start</dfn>, <dfn>span-self-y-end</dfn>
+	: <dfn>span-x-start</dfn>, <dfn>span-x-end</dfn>, <dfn>span-self-x-start</dfn>, <dfn>span-self-x-end</dfn>
 	: <dfn>span-block-start</dfn>, <dfn>span-block-end</dfn>, <dfn>span-self-block-start</dfn>, <dfn>span-self-block-end</dfn>
 	: <dfn>span-inline-start</dfn>, <dfn>span-inline-end</dfn>, <dfn>span-self-inline-start</dfn>, <dfn>span-self-inline-end</dfn>
 	: <dfn>span-all</dfn>