📝 add more docs (#5231)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json/emplace.md

@@ -64,6 +64,7 @@ Logarithmic in the size of the container, O(log(`size()`)).
 
 - [emplace_back](emplace_back.md) add a value to an array
 - [insert](insert.md) add values to an array/object
+- [Modifying values](../../features/modifying_values.md) - the article on modifying values
 
 ## Version history