Write up deprecate dynamic plugins (bevyengine#1210)

Co-authored-by: Alice Cecile <[email protected]>

release-content/0.14/release-notes/13080_Deprecate_dynamic_plugins.md

@@ -1 +1,8 @@
-TODO
+`bevy_dynamic_plugin` was a tool added in Bevy's original 0.1 release: intended to serve as a tool for dynamically loading / linking Rust code for use with things like modding.
+Unfortunately, this feature didn't see much community uptake, and as a result had a vanishingly small number of contributions to refine and document it over the years.
+
+Combined with a challenging, intrinsically unsafe API that was producing [worrying failures](https://github.com/bevyengine/bevy/issues/13073) for users, we've decided to deprecate `bevy_dynamic_plugin` and will be removing it completely in Bevy 0.15.
+If you were a happy user of this, simply copy the rather-small crate into your own project and proceed as before.
+
+We still think that both modding and hot-reloading code for faster development times are valuable use cases that Bevy *should* help support one day.
+Our hope is that by removing this as a first-party crate, we can spur on third-party experiments and avoid wasting users' time as they investigate a complex potential solution before concluding that it doesn't yet meet their needs.