docs: add announcement

announcements-extra.json

@@ -1,2 +1,7 @@
 [
+  {
+    "id": "#2639",
+    "title": "Need Help! Please test the next version (1.107.1) on Linux arm64",
+    "url": "https://github.com/VSCodium/vscodium/discussions/2639"
+  }
 ]