test: 新增 Demo26 演示程序

playground/Demo/Demo26/Main.snow

@@ -0,0 +1,20 @@
+module: Main
+    function: main
+        returns: void
+        body:
+            // 1. 常见转义符
+            declare sNewline  : string = "换行示例:\n第二行"
+            declare sTab      : string = "制表符示例:\t列二"
+            declare sBackslash: string = "反斜杠示例: C:\\Snow"
+            declare sDQuote   : string = "双引号示例: \"Snow\""
+            declare sSQuote   : string = "单引号示例: \'Snow\'"
+            declare sCarriage : string = "回车示例:\rCarriage"
+            declare sBackspace: string = "退格示例: ABC\bD"
+            declare sFormFeed : string = "换页示例:\fPage-2"
+
+            // 2. Unicode 转义
+            declare sUnicode  : string = "𪚥𠮷: \u4F60\u597D, Snow!"
+
+        end body
+    end function
+end module