Automatic readme update

README.md

@@ -15,19 +15,14 @@ contributors](https://img.shields.io/github/contributors/epiforecasts/bpmodels)
 MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/license/MIT/)
 <!-- badges: end -->
 
-<div style="background-color: #ffcccc; border: 1px solid #ff0000; padding: 10px; margin-bottom: 20px;">
-
-<strong style="color: #ff0000;">️ WARNING:</strong>
-<p style="margin: 0;">
-`{bpmodels}` is now *retired and will no longer be maintained*. We
-recommend using
-[`{epichains}`](https://github.com/epiverse-trace/epichains) instead. If
-you need help converting your code to use `{epichains}`, please [open a
-discussion on
-epichains](https://github.com/epiverse-trace/epichains/discussions).
-</p>
-
-</div>
+## WARNING
+
+> `{bpmodels}` is now *retired and will no longer be maintained*. We
+> recommend using
+> [`{epichains}`](https://github.com/epiverse-trace/epichains) instead.
+> If you need help converting your code to use `{epichains}`, please
+> [open a discussion on
+> epichains](https://github.com/epiverse-trace/epichains/discussions).
 
 *bpmodels* is an R package to simulate and analyse the size and length
 of branching processes with a given offspring distribution. These models