add changelog for 1.21.5

Katie Horne · Katie Horne · commit 3f2887f02c3d · 2021-09-29T09:44:32.000-05:00
diff --git a/manifest.json b/manifest.json
@@ -411,6 +411,9 @@
     {
       "path": "./changelog/index.md",
       "children": [
+        {
+          "path": "./changelog/1.21.5.md"
+        },
         {
           "path": "./changelog/1.21.4.md"
         },
