chore(docs): add example to gallery

CHANGELOG.md

@@ -24,6 +24,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   when using one of those extras, but as they were not part of the public API,
   we do not consider this to be a **breaking change**.
   [#542](https://github.com/jeertmans/manim-slides/pull/542)
+- Added example in the research section of the gallery.
+  [@mmcilree](https://github.com/mmcilree) [#552](https://github.com/jeertmans/manim-slides/pull/552)
+- Added example in the school work section of the gallery.
+  [@casperalgera](https://github.com/casperalgera) [#556](https://github.com/jeertmans/manim-slides/pull/556)
 
 (v5.5.1)=
 ## [v5.5.1](https://github.com/jeertmans/manim-slides/compare/v5.5.0...v5.5.1)

docs/source/gallery.md

@@ -93,5 +93,21 @@ Here are the slides from a 25-minute talk he presented at the 39th Annual AAAI C
 
 Below are people that used Manim Slides for school presentations.
 
-*This list is currently empty. Please reach out to us if you have examples
-to share!*
+### Casper Algera
+
+Casper, a mathematics student from the Netherlands, used Manim Slides to present his bachelor's thesis.
+In his presentation, he illustrates a probabilistic coupling argument related to the [contact process](https://en.wikipedia.org/wiki/Contact_process_(mathematics)).
+His slides are available below, and his full presentation can be viewed on [YouTube](https://www.youtube.com/watch?v=ZJhvfCL5MWE).
+
+<div style="position:relative;padding-bottom:56.25%;">
+    <iframe
+        loading="lazy"
+        style="width:100%;height:100%;position:absolute;left:0px;top:0px;"
+        frameborder="1"
+        width="100%"
+        height="100%"
+        allowfullscreen
+        allow="autoplay"
+        src="https://casperalgera.github.io/criticalvalueCP/">
+    </iframe>
+</div>