Update method-syntax.md

make the definition of static methods explicit

Author: acgtyrant

src/doc/trpl/method-syntax.md

@@ -129,7 +129,7 @@ circle to any arbitrary size.
 
 # Static methods
 
-You can also define methods that do not take a `self` parameter. Here’s a
+You can also define static methods that do not take a `self` parameter. Here’s a
 pattern that’s very common in Rust code:
 
 ```