fix homepage + typo

Author: nwah

app/components/App.js

@@ -18,7 +18,7 @@ const App = ({children, location}) => (
     </div>
     <CourseIndex location={location} />
     <div className="app__footer">
-      Written, designed, and built by <a href="http://noahburney.com" target="_blank">Noah Burney</a>.
+      Written, designed, and built by <a href="http://noahburney.net" target="_blank">Noah Burney</a>.
       See <a href="/credits">audio and photo credits</a>.
     </div>
   </div>

app/data/course.js

@@ -49,7 +49,7 @@ Take a look at the arrangement of the letters within each block.
 ---
 In **kim**, the ㄱ and ㅣ are stacked on top of the ㅁ, but in **chi** the ㅊ and ㅣ are sitting side-by-side.
 ---
-Any time the the vowel is tall and skinny like **ㅣ** we arrange the letters like this.
+Any time the vowel is tall and skinny like **ㅣ** we arrange the letters like this.
           `,
           start: `
 Let’s try some reading!