Update dual_language_caption.md

docs/FAQ/dual_language_caption.md

@@ -4,12 +4,24 @@ tags: [figure, show]
 
 # figure 的 caption 如何实现双语？
 
-我个人推荐封装一个myfig(body, zhcaption, encaption)
-
-然后调用figure(body, kind: 'myfig', caption: metadata((.......zhcaption......encaption)))
-
-然后show figure.where(kind: 'myfig')从metadata里把双语拿出来
+可以把双语用 `metadata` 存到 `caption` 里面，然后在 `show figure` 里面把双语拿出来
 
 ```typst
-等人来写（）
+#let bifig(body, capzh, capen) = figure(
+  body,
+  supplement: none,
+  kind: "bifig",
+  caption: metadata((capzh, capen)),
+)
+#show figure.where(kind: "bifig"): it => {
+  let (capzh, capen) = it.caption.body.value
+  let c = it.counter.display("1")
+  it.body
+  parbreak()
+  [图 #c: #capzh]
+  parbreak()
+  [Figure #c: #capen]
+}
+
+#bifig(rect(), "启动", "start")
 ```