Update command to run the Firestore emulator (#2998)

dconeybe · web-flow · commit 9f7b7df7d4b6 · 2020-05-01T20:05:24.000-04:00
diff --git a/packages/firestore/CONTRIBUTING.md b/packages/firestore/CONTRIBUTING.md
@@ -34,7 +34,7 @@ on port 8080, which is default when running it via CLI.
     ```
   * Run the emulator
     ```
-    firebase serve --only firestore
+    firebase emulators:start --only firestore
     ```
 
 ### Running Firestore Tests
