feat: 添加取模运算符支持，更新解析器、解释器、词法分析器和相关示例以处理相关语法

src/parser/parser.rs

@@ -212,6 +212,8 @@ impl Parser {
             Some(AssignOp::StarEqual)
         } else if self.match_kind(&[TokenKind::SlashEqual]) {
             Some(AssignOp::SlashEqual)
+        } else if self.match_kind(&[TokenKind::PercentEqual]) {
+            Some(AssignOp::PercentEqual)
         } else {
             None
         };
@@ -324,10 +326,11 @@ impl Parser {
     fn factor(&mut self) -> Expr {
         let mut expr = self.unary();
 
-        while self.match_kind(&[TokenKind::Star, TokenKind::Slash]) {
+        while self.match_kind(&[TokenKind::Star, TokenKind::Slash, TokenKind::Percent]) {
             let op = match self.previous().kind {
                 TokenKind::Star => BinaryOp::Mul,
                 TokenKind::Slash => BinaryOp::Div,
+                TokenKind::Percent => BinaryOp::Mod,
                 _ => unreachable!(),
             };
             let right = self.unary();