Typo fix.

Author: SimonSapin

ast.rs

@@ -43,7 +43,7 @@ pub enum ComponentValue {
     Colon,  // :
     Semicolon,  // ;
     Comma,  // ,
-    IncludeMath, // ~=
+    IncludeMatch, // ~=
     DashMatch, // |=
     PrefixMatch, // ^=
     SuffixMatch, // $=

tokenizer.rs

@@ -238,7 +238,7 @@ fn next_component_value(tokenizer: &mut Tokenizer) -> Option<Node> {
         },
         '}' => { tokenizer.position += 1; CloseCurlyBracket },
         '~' => {
-            if tokenizer.starts_with("~=") { tokenizer.position += 2; IncludeMath }
+            if tokenizer.starts_with("~=") { tokenizer.position += 2; IncludeMatch }
             else { tokenizer.position += 1; Delim(c) }
         },
         _ => {