add ref with count test

test/unit/elements/reference/count/.gitignore

@@ -0,0 +1 @@
+# added by typst-test

test/unit/elements/reference/count/test.typ

@@ -0,0 +1,35 @@
+#import "/test/unit/base.typ": template
+#show: template
+#set text(5pt)
+
+#import "/src/lib.typ" as e: field
+
+#show ref: e.ref
+
+#let wock = e.element.declare(
+  "wock",
+  display: it => {
+    rect(width: 2.5pt, height: 2.5pt, fill: blue)
+  },
+  fields: (
+    field("depth", int, default: 1),
+    field("offset", int, default: 0),
+    field("run", function, default: () => {})
+  ),
+  synthesize: it => {
+    it.level = it.depth + it.offset
+    it
+  },
+  count: c => it => c.step(level: it.level),
+  reference: (
+    supplement: [Wock],
+    numbering: "1.1"
+  ),
+  prefix: ""
+)
+
+#wock(label: <my-wock>)
+@my-wock
+
+#wock(depth: 2, label: <my-wock2>)
+@my-wock2[abc]