chore: add 1.21.2 changelog

Katie Horne · Katie Horne · commit 14c66f211316 · 2021-08-26T14:56:43.000-05:00
diff --git a/manifest.json b/manifest.json
@@ -411,6 +411,9 @@
     {
       "path": "./changelog/index.md",
       "children": [
+        {
+          "path": "./changelog/1.21.2.md"
+        },
         {
           "path": "./changelog/1.21.1.md"
         },
