Add Apollo 11 audio demo file and update references from .wav to .mp3

app/src/content/assets/audio/audio-example.mp3

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:25334bdbaf5980acb854078acdbeb9f413f2ff71be3874e77fb5cd175403d2c9
+size 146330

app/src/content/chapters/demo/components.mdx

@@ -1,6 +1,6 @@
 import { Image as AstroImage } from 'astro:assets';
 import placeholder from '../../assets/image/placeholder.png';
-import audioDemo from '../../assets/audio/audio-example.wav';
+import audioDemo from '../../assets/audio/audio-example.mp3';
 import HtmlEmbed from '../../../components/HtmlEmbed.astro';
 import Sidenote from '../../../components/Sidenote.astro';
 import Wide from '../../../components/Wide.astro';

app/src/content/chapters/demo/markdown.mdx

@@ -1,5 +1,5 @@
 import placeholder from '../../assets/image/placeholder.png';
-import audioDemo from '../../assets/audio/audio-example.wav';
+import audioDemo from '../../assets/audio/audio-example.mp3';
 import HtmlEmbed from '../../../components/HtmlEmbed.astro';
 import Sidenote from '../../../components/Sidenote.astro';
 import Wide from '../../../components/Wide.astro';
@@ -453,7 +453,7 @@ Embed audio using `<audio controls src={...} />`.
 <br/>
 <Accordion title="Code example">
 ```mdx
-import audioDemo from './assets/audio/audio-example.wav'
+import audioDemo from './assets/audio/audio-example.mp3'
 
 <audio controls src={audioDemo}/>
 ```

app/src/content/chapters/demo/writing-your-content.mdx

@@ -8,7 +8,7 @@ import FullWidth from '../../../components/FullWidth.astro';
 import HtmlEmbed from '../../../components/HtmlEmbed.astro';
 import ColorPicker from '../../../components/demo/ColorPicker.astro';
 import Palettes from '../../../components/demo/Palettes.astro';
-import audioDemo from '../../assets/audio/audio-example.wav';
+import audioDemo from '../../assets/audio/audio-example.mp3';
 import Accordion from '../../../components/Accordion.astro';
 
 ## Writing your content