Update step1-06/demo/README.md

Co-Authored-By: mattpham <jumpdownlow@gmail.com>

step1-06/demo/README.md

@@ -109,7 +109,7 @@ Typically, a controlled input's current value is stored in the parent component'
 
 > The distinction between controlled and uncontrolled is important to understand when writing or using form components, and misunderstandings of this concept are a very common source of bugs. See [this article](https://goshakkk.name/controlled-vs-uncontrolled-inputs-react/) for a more detailed explanation.
 
-Lets try changing the text field in our `TodoHeader` component to a controlled input. To add a controlled input, we need two things, which our demo already provides:
+Let's try changing the text field in our `TodoHeader` component to a controlled input. To add a controlled input, we need two things, which our demo already provides:
 
 1. A state variable to hold the input's value: