Return Option<Value> from fun on replace_with to all user to return None (remove the value and not replace with Null)

tests/readme.rs

@@ -224,7 +224,7 @@ fn readme_selector_mut() {
                 0
             };
 
-            json!(age)
+            Some(json!(age))
         })
         .unwrap()
         .take()
@@ -522,7 +522,7 @@ fn readme_replace_with() {
             0
         };
 
-        json!(age)
+        Some(json!(age))
     })
     .unwrap();
 

tests/selector.rs

@@ -23,7 +23,7 @@ fn selector_mut() {
             if let Value::Number(n) = v {
                 nums.push(n.as_f64().unwrap());
             }
-            Value::String("a".to_string())
+            Some(Value::String("a".to_string()))
         })
         .unwrap()
         .take()