Add image capture slide

src/index.html

@@ -143,6 +143,14 @@
             </aside>
           </section>
         </section>
+        <section data-background-image="https://images.unsplash.com/flagged/photo-1562599838-8cc871c241a5">
+          <h2 class="r-fit-text text-shadow">1. Capture an image</h2>
+          <aside class="notes" data-markdown>
+            - Need a camera
+            - Read an image
+            - Image is just pixels (RGB)
+          </aside>
+        </section>
       </div>
     </div>
     <script type="module" src="./index.js"></script>