Grammatically updated the css value docs

Author: mitp7

css-values-3/Overview.bs

@@ -1283,7 +1283,7 @@ Absolute Lengths: the ''cm'', ''mm'', ''Q'', ''in'', ''pt'', ''pc'', ''px'' unit
 		    <td>1pc = 1/6th of 1in
 		<tr><th><dfn id="pt">pt</dfn>
 		    <td>points
-		    <td>1pt = 1/72th of 1in
+		    <td>1pt = 1/72nd of 1in
 		<tr><th><dfn id="px" lt="px">px</dfn>
 		    <td>pixels
 		    <td>1px = 1/96th of 1in

css-values-4/Overview.bs

@@ -2021,7 +2021,7 @@ Absolute Lengths: the ''cm'', ''mm'', ''Q'', ''in'', ''pt'', ''pc'', ''px'' unit
 		    <td>1pc = 1/6th of 1in
 		<tr><th><dfn id="pt">pt</dfn>
 		    <td>points
-		    <td>1pt = 1/72th of 1in
+		    <td>1pt = 1/72nd of 1in
 		<tr><th><dfn id="px" lt="px">px</dfn>
 		    <td>pixels
 		    <td>1px = 1/96th of 1in