Update README.md to reflect latest status

PiperOrigin-RevId: 292543116

Author: wu-hui

firestore/README.md

@@ -21,7 +21,7 @@ with all possible setups.
 ### Against Firestore emulator
 
 This is the preferred way to run integration tests. The way it is configured is
-we have a controlling `go_test` (`integration_test_emulator.go`), which will
+we have a controlling `sh_test` (`integration_test_emulator.sh`), which will
 pull Firestore emulator as a `data` dependency and set it up before it finds and
 runs the actual integration tests in separate processes.
 
@@ -61,6 +61,13 @@ impossible (such as Forge).
 It is useful still, for example, to run it before a release or to debug issues
 that only happen with real backend.
 
+#### Linux:
+
+```bash
+# Run the tests locally (`--test_output=streamed`) so they have network access.
+blaze test --test_output=streamed //firebase/firestore/client/cpp:cc_tests
+```
+
 #### iOS (Runs on real devices via MobileHarness):
 
 ```bash