[css-values-4] Fix simple copy/paste typos in new root-element font-relative units. (w3c#6745)

Author: jfkthame

css-values-4/Overview.bs

@@ -1672,7 +1672,7 @@ Font-relative Lengths: the ''em'', ''rem'', ''ex'', ''rex'', ''cap'', ''rcap'',
 
 		<dt><dfn id="rex" lt="rex">rex unit</dfn>
 		<dd>
-			Equal to the value of the ''rex'' unit on the root element.
+			Equal to the value of the ''ex'' unit on the root element.
 
 		<dt><dfn id="cap" lt="cap">cap unit</dfn>
 		<dd>
@@ -1691,7 +1691,7 @@ Font-relative Lengths: the ''em'', ''rem'', ''ex'', ''rex'', ''cap'', ''rcap'',
 
 		<dt><dfn id="rcap" lt="rcap">rcap unit</dfn>
 		<dd>
-			Equal to the value of the ''rcap'' unit on the root element.
+			Equal to the value of the ''cap'' unit on the root element.
 
 		<dt><dfn id="ch" lt="ch">ch unit</dfn>
 		<dd>
@@ -1733,7 +1733,7 @@ Font-relative Lengths: the ''em'', ''rem'', ''ex'', ''rex'', ''cap'', ''rcap'',
 
 		<dt><dfn id="rch" lt="rch">rch unit</dfn>
 		<dd>
-			Equal to the value of the ''rch'' unit on the root element.
+			Equal to the value of the ''ch'' unit on the root element.
 
 		<dt><dfn id="ic" lt="ic">ic unit</dfn>
 		<dd>
@@ -1762,7 +1762,7 @@ Font-relative Lengths: the ''em'', ''rem'', ''ex'', ''rex'', ''cap'', ''rcap'',
 
 		<dt><dfn id="ric" lt="ric">ric unit</dfn>
 		<dd>
-			Equal to the value of the ''ric'' unit on the root element.
+			Equal to the value of the ''ic'' unit on the root element.
 
 		<dt><dfn id="lh" lt="lh">lh unit</dfn>
 		<dd>