Added diff to the tool

examples/test_schema_modified.dbml

@@ -0,0 +1,31 @@
+// Modified test schema for diff testing
+Table public.users {
+  id bigint [pk, increment]
+  email varchar(255) [unique, not null]
+  name varchar(150) // Changed from 100 to 150
+  phone varchar(20) // New column
+  created_at timestamp [not null]
+  updated_at timestamp
+}
+
+Table public.posts {
+  id bigint [pk, increment]
+  user_id bigint [not null]
+  title varchar(200) [not null]
+  content text
+  published boolean [default: true] // Changed default from false to true
+  views integer [default: 0] // New column
+  created_at timestamp [not null]
+}
+
+Table public.comments {
+  id bigint [pk, increment]
+  post_id bigint [not null]
+  user_id bigint [not null]
+  content text [not null]
+  created_at timestamp [not null]
+}
+
+Ref: public.posts.user_id > public.users.id [ondelete: CASCADE]
+Ref: public.comments.post_id > public.posts.id [ondelete: CASCADE]
+Ref: public.comments.user_id > public.users.id