Clarify index.js description

- When I first saw the site description, I thought WEBMIDI.js was warning you about itself, not the original js API!

website/src/pages/index.js

@@ -42,9 +42,9 @@ function Presentation() {
           type="col-2"
         >
           <p>
-            The <strong>Web MIDI API</strong> is a really exciting addition to the web platform
+            The existing <strong>Web MIDI API</strong> is a really exciting addition to the web platform
             allowing a web page to interact with <strong>MIDI musical instruments</strong>.
-            However, while great, most developers will find the API to be
+            However, while great, most developers will find the original API to be
             too <em>low-level</em> for their needs. Having to perform binary arithmetic
             or needing to read the 300-page MIDI spec is no fun (trust us on this!).
             The goal behind <strong>WEBMIDI.js</strong> is to get you started with your web-based