Updated the changelog

.changeset/add-nested-namespaces.md

@@ -0,0 +1,17 @@
+---
+'@mermaid': patch
+---
+
+Fixed an issue when the mermaid classdiagram crashes when adding a . to the namespace.
+Forexample
+
+```mermaid
+
+classDiagram
+  namespace Company.Project.Module {
+    class GenericClass~T~ {
+      +addItem(item: T)
+      +getItem() T
+    }
+  }
+```