Update dictionary.insert() doc and tests (#3343)

crates/typst/src/foundations/dict.rs

@@ -182,8 +182,8 @@ impl Dict {
             .ok_or_else(|| missing_key_no_default(&key))
     }
 
-    /// Inserts a new pair into the dictionary and return the value. If the
+    /// Inserts a new pair into the dictionary. If the dictionary already
-    /// dictionary already contains this key, the value is updated.
+    /// contains this key, the value is updated.
     #[func]
     pub fn insert(
         &mut self,

tests/typ/compiler/dict.typ

@@ -40,6 +40,16 @@
 #test((a: 1, b: 2).at("b", default: 3), 2)
 #test((a: 1, b: 2).at("c", default: 3), 3)
 
+---
+// Test insert.
+#{
+  let dict = (a: 1, b: 2)
+  dict.insert("b", 3)
+  test(dict, (a: 1, b: 3))
+  dict.insert("c", 5)
+  test(dict, (a: 1, b: 3, c: 5))
+}
+
 ---
 // Test remove with default value.
 #{