docs: add Alexander Carr testimonial

src/content/testimonial/alexander-carr.json

@@ -0,0 +1,7 @@
+{
+  "name": "Alexander Carr",
+  "tagline": "Full Stack Software Engineer at School of Code",
+  "text": "<p>Hi Oliver, we met briefly at the Tech Connect event in London last month. Been reading through a few of your latest posts and have found the messages valuable, especially as we spent the week learning about unit, integration and e2e testing. I have signed up to your mailing list to keep the good advice flowing!</p>",
+  "image": "alexander-carr.jpg",
+  "url": null
+}

src/pages/daily.mdx

@@ -2,6 +2,7 @@
 layout: ~/layouts/PageLayout.astro
 title: Oliver's Daily List
 testimonials:
+  - alexander-carr
   - adam-nuttall
   - mike-karthauser
   - marcos-duran