fix links (#123)

* fix link

* fix links

src/exercise/01.md

@@ -83,7 +83,7 @@ function App() {
 ```
 
 > You can pull this example up here:
-> http://localhost:3000/isolated/examples/counter-before.js
+> [/isolated/examples/counter-before.js](http://localhost:3000/isolated/examples/counter-before.js)
 
 I want to focus in on the user of our reducer (the `Counter` component). Notice
 that they have to create their own `increment` and `decrement` functions which

src/exercise/06.md

@@ -20,7 +20,7 @@ Props."
 
 This concept is basically the same as controlled form elements in React that
 you've probably used many times: 📜
-https://react.dev/reference/react-dom/components
+<https://react.dev/reference/react-dom/components#form-components>
 
 ```javascript
 function MyCapitalizedInput() {
@@ -100,11 +100,11 @@ Warning: Failed prop type: You provided a `value` prop to a form field without a
 ```
 
 ```
-Warning: A component is changing an uncontrolled input of type undefined to be controlled. Input elements should not switch from uncontrolled to controlled (or vice versa). Decide between using a controlled or uncontrolled input element for the lifetime of the component. More info: https://fb.me/react-controlled-components
+Warning: A component is changing an uncontrolled input of type undefined to be controlled. Input elements should not switch from uncontrolled to controlled (or vice versa). Decide between using a controlled or uncontrolled input element for the lifetime of the component. More info: https://react.dev/reference/react-dom/components/input#controlling-an-input-with-a-state-variable
 ```
 
 ```
-Warning: A component is changing a controlled input of type undefined to be uncontrolled. Input elements should not switch from controlled to uncontrolled (or vice versa). Decide between using a controlled or uncontrolled input element for the lifetime of the component. More info: https://fb.me/react-controlled-components
+Warning: A component is changing a controlled input of type undefined to be uncontrolled. Input elements should not switch from controlled to uncontrolled (or vice versa). Decide between using a controlled or uncontrolled input element for the lifetime of the component. More info: https://react.dev/reference/react-dom/components/input#controlling-an-input-with-a-state-variable
 ```
 
 We should issue the same warnings for people who misuse our controlled props: