Create lucky-games-arrive.md

Author: MarkDuckworth

.changeset/lucky-games-arrive.md

@@ -0,0 +1,8 @@
+---
+"@firebase/firestore": minor
+"firebase": minor
+---
+
+Functions in the Firestore package that return QueryConstraints (for example: `where(...)`, `limit(...)`, and `orderBy(...)`)
+now return a more specific type, which extends QueryConstraint. Refactoring and code that supports future features is also
+included in this release.