Fix a mistake in release notes for 1.21.0

Also reorder changes to put the important one first.

Author: petrochenkov

RELEASES.md

@@ -3,19 +3,19 @@ Version 1.21.0 (2017-10-12)
 
 Language
 --------
-- [Relaxed path syntax. You can now add type parameters to values][43540]
-  Example:
-  ```rust
-  my_macro!(Vec<i32>::new); // Always worked
-  my_macro!(Vec::<i32>::new); // Now works
-  ```
 - [You can now use static references for literals.][43838]
   Example:
   ```rust
   fn main() {
       let x: &'static u32 = &0;
   }
   ```
+- [Relaxed path syntax. Optional `::` before `<` is now allowed in all contexts.][43540]
+  Example:
+  ```rust
+  my_macro!(Vec<i32>::new); // Always worked
+  my_macro!(Vec::<i32>::new); // Now works
+  ```
 
 Compiler
 --------