chore: Update testimonials

[darcywong00]

I was going to just add an entry to the top of the testimonial page.

Changes

• Add an entry to the top of the testimonial page
• Converted half (headers and captions) of the page to Markdown.
• I also had to move a lot of closing </p> tags for the captions to show.
  Note: ll 123-135 were unchanged so that's the pattern I followed.

I tried setting testimonials like

### I would earnestly like to thank you for the best multilingual keyboard, especially for us [#Ethiopians](https://twitter.com/hashtag/Ethiopians?src=hashtag_click) using [#Geez](https://twitter.com/hashtag/Geez?src=hashtag_click) scripts. It’s simply excellent. {.testimonial}

but the text doesn't quite style right

Original

<p class="center">
  <span class="testimonial">I would earnestly like to thank you for the best multilingual keyboard, especially for us <a href="https://twitter.com/hashtag/Ethiopians?src=hashtag_click">#Ethiopians</a> using <a href="https://twitter.com/hashtag/Geez?src=hashtag_click">#Geez</a> scripts. It’s simply excellent.</span>
</p>

[darcywong00]

Screenshot of how the Markdown renders