[css-syntax] typos

Author: tabatkins

css-syntax/Overview.bs

@@ -3360,7 +3360,7 @@ Changes from CSS 2.1 and Selectors Level 3</h3>
 			The <<comma-token>> has been added.
 
 		<li>
-			<<number-token>>, <<number-token>>, and <<dimension-token>> have been changed
+			<<number-token>>, <<percentage-token>>, and <<dimension-token>> have been changed
 			to include the preceding +/- sign as part of their value
 			(rather than as a separate <<delim-token>> that needs to be manually handled every time the token is mentioned in other specs).
 			The only consequence of this is that comments can no longer be inserted between the sign and the number.
@@ -3383,12 +3383,12 @@ Changes from CSS 2.1 and Selectors Level 3</h3>
 
 	<ul>
 		<li>
-			Any list of declaration now also accepts at-rules, like ''@page'',
+			Any list of declarations now also accepts at-rules, like ''@page'',
 			per WG resolution.
 			This makes a difference in error handling
 			even if no such at-rules are defined yet:
-			an at-rule, valid or not, ends and lets the next declaration being
-			at a {} block without a <<semicolon-token>>.
+			an at-rule, valid or not, ends at a {} block without a <<semicolon-token>>
+			and lets the next declaration begin.
 
 		<li>
 			The handling of some miscellanous "special" tokens