Fix typo in update instructions.mdx (#109)

Author: hey-august

content/03-Objects/02-Additional-Properties/instructions.mdx

@@ -9,7 +9,7 @@ keywords: additional properties, object, JSON Schema, properties, type, properti
 
 In the previous lesson, we have set `additionalProperties` to `false`. What does it mean? 
 
-So far, we have seen how to define the properties of an object in a [schema](https://json-schema.org/learn/glossary#schema). But **what if you want to specify constrains for the properties which you have not defined in the schema?**
+So far, we have seen how to define the properties of an object in a [schema](https://json-schema.org/learn/glossary#schema). But **what if you want to specify constraints for the properties which you have not defined in the schema?**
 
 The `additionalProperties` [keyword](https://json-schema.org/learn/glossary#keyword) is used to control the handling of extra stuff, that is, properties whose names are not listed in the `properties` keyword or match any of the regular expressions in the `patternProperties` keyword. 
 
@@ -50,4 +50,4 @@ You can also set `additionalProperties` to a schema to define the schema for the
 
 The above schema will allow only `name` and `age` properties in the object. If any other property is present in the object, it should be of type `string`.
 
-Now, try to modify the schema provided in the <SideEditorLink/> on the right to allow any additional properties of type `integer`.
+Now, try to modify the schema provided in the <SideEditorLink/> on the right to allow any additional properties of type `integer`.