feat: add example scripts for argparse, bytes, dataset, html, markdown, uuid, wdantic, and web chat modules

Add comprehensive demo scripts showcasing the usage of multiple Wren modules including argument parsing, byte manipulation, in-memory dataset operations, HTML encoding/slugification, markdown-to-HTML conversion, UUID generation/validation, schema validation with wdantic, and a full web chat application with REST endpoints.

test/dataset/auto_schema.wren

@@ -0,0 +1,20 @@
+// retoor <retoor@molodetz.nl>
+
+import "dataset" for Dataset
+
+var ds = Dataset.memory()
+
+var users = ds["users"]
+users.insert({"name": "Alice"})
+
+var cols1 = users.columns
+System.print(cols1.containsKey("uid")) // expect: true
+System.print(cols1.containsKey("name")) // expect: true
+System.print(cols1.containsKey("email")) // expect: false
+
+users.insert({"name": "Bob", "email": "bob@example.com"})
+
+var cols2 = users.columns
+System.print(cols2.containsKey("email")) // expect: true
+
+ds.close()