fix: typo in context name FootContext -> FooterContext (#135)

* fix: update title in README to reflect React Performance title

* fix: typo in context name FootContext -> FooterContext

Author: rubenpenap

exercises/02.context/02.problem.provider-component/index.tsx

@@ -10,7 +10,7 @@ const FooterContext = createContext<{
 
 // 🐨 create a FooterProvider component here and move the color and name state
 // and context value to this component.
-// 💰 Make sure to accept a children prop and render the FootContext with it
+// 💰 Make sure to accept a children prop and render the FooterContext with it
 
 function useFooter() {
 	const context = use(FooterContext)