chore: flatten src/ to root

ink/hooks/use-app.ts

@@ -0,0 +1,8 @@
+import { useContext } from 'react'
+import AppContext from '../components/AppContext.js'
+
+/**
+ * `useApp` is a React hook, which exposes a method to manually exit the app (unmount).
+ */
+const useApp = () => useContext(AppContext)
+export default useApp