Chagne all firebase --use add to firebase use --add

Author: whhone

assistant-say-number/README.md

@@ -22,7 +22,7 @@ The dependencies are listed in [functions/package.json](functions/package.json).
 To test this sample action:
 
  - Create a Firebase Project using the [Firebase Developer Console](https://console.firebase.google.com)
- - Configure this sample to use your project using `firebase --use add` and select your project.
+ - Configure this sample to use your project using `firebase use --add` and select your project.
  - Deploy your project using `firebase deploy`
  - In the `action.json` file, update the two `<YOUR_PROJECT_ID>` placeholders with your Firebase project ID. The URL should match the `Function URL (sayNumber):` that was printed out by `firebase deploy`.
  - [Download](https://developers.google.com/actions/tools/gactions-cli) the `gaction` CLI

github-to-slack/README.md

@@ -20,7 +20,7 @@ To test this integration:
 
  - Create a Firebase Project using the [Firebase Developer Console](https://console.firebase.google.com)
  - Enable billing on your project by switching to the Blaze or Flame plan. See [pricing](https://firebase.google.com/pricing/) for more details. This is required to be able to do requests to non-Google services.
- - Configure this sample to use your project using `firebase --use add` and select your project.
+ - Configure this sample to use your project using `firebase use --add` and select your project.
  - Install dependencies locally by running: `cd functions; npm install; cd -`
  - [Add a WebHook to your GitHub repo](https://help.github.com/articles/about-webhooks/) with the following settings:
    - Payload URL: `https://us-central1-<FIREBASE_PROJECT_ID>.cloudfunctions.net/githubWebhook`

typescript-getting-started/README.md

@@ -78,7 +78,7 @@ starter project:
    PROJECT=your-project-name
    mkdir $PROJECT; cd $PROJECT
    firebase init
-   firebase --use add $PROJECT
+   firebase use --add $PROJECT
    rm -rf functions
    cp -r ../functions-samples/typescript-getting-started/functions functions
    ```