fix(challenges): typo

fix typo on line 2083, from 'mutatable' to 'mutable'

challenges/03-front-end-libraries/react.json

@@ -2080,7 +2080,7 @@
       "title": "Create a Controlled Input",
       "releasedOn": "December 25, 2017",
       "description": [
-        "Your application may have more complex interactions between <code>state</code> and the rendered UI. For example, form control elements for text input, such as <code>input</code> and <code>textarea</code>, maintain their own state in the DOM as the user types. With React, you can move this mutatable state into a React component's <code>state</code>. The user's input becomes part of the application <code>state</code>, so React controls the value of that input field. Typically, if you have React components with input fields the user can type into, it will be a controlled input form.",
+        "Your application may have more complex interactions between <code>state</code> and the rendered UI. For example, form control elements for text input, such as <code>input</code> and <code>textarea</code>, maintain their own state in the DOM as the user types. With React, you can move this mutable state into a React component's <code>state</code>. The user's input becomes part of the application <code>state</code>, so React controls the value of that input field. Typically, if you have React components with input fields the user can type into, it will be a controlled input form.",
         "<hr>",
         "The code editor has the skeleton of a component called <code>ControlledInput</code> to create a controlled <code>input</code> element. The component's <code>state</code> is already initialized with an <code>input</code> property that holds an empty string. This value represents the text a user types into the <code>input</code> field.",
         "First, create a method called <code>handleChange()</code> that has a parameter called <code>event</code>. When the method is called, it receives an <code>event</code> object that contains a string of text from the <code>input</code> element. You can access this string with <code>event.target.value</code> inside the method. Update the <code>input</code> property of the component's <code>state</code> with this new string.",