add demo text; made executable for the demo

resources/test/example_1.sil

@@ -0,0 +1,18 @@
+(container []
+	(header []
+		(title [] |Demo #1|)
+	)
+	(main []
+		(std<Image> [alt="hoge" ref="./upload/hoge.jpg"])
+		(section [lang=md ] |\
+      # Hello, world!\
+      This is a simple example of SIL.\
+		|)
+	)
+	(footer []
+		(card []
+			(icon<Image> [src="/icon.png" alt="Cute icon" on:click="alert('Hello!')"])
+			(copyright [] |Copyright here.|)
+		)
+	)
+)

src/om/tokenizer.rs

@@ -164,7 +164,9 @@ impl Iterator for Tokenizer {
                         return self.latest.take();
                     }
                     x => {
-                        if !x.is_ascii_alphanumeric() && x != '=' && x != ':' {
+                        if !x.is_ascii_alphanumeric()
+                            && !vec!['=', ':', '"', '\'', '.', '/', '(', ')', '!'].contains(&x)
+                        {
                             panic!("Unexpected character: {}", x);
                         }
                         self.buffer.push(x);
@@ -210,6 +212,11 @@ impl Iterator for Tokenizer {
                         }
                     }
                 },
+                State::InQuote => match c {
+                    '"' => todo!(),
+                    _ => todo!(),
+                },
+                State::InDoubleQuote => todo!(),
             }
         }
     }
@@ -224,6 +231,9 @@ enum State {
     AfterDefine,
     Behavior,
     BehaviorSeparator,
+
+    InQuote,
+    InDoubleQuote,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]