Fix typos (#907)

Author: rmschindler

username-password-auth/README.md

@@ -4,16 +4,16 @@ This sample shows how to authenticate with a username/password to Sign-In with F
 
 NOTE: [Firebase Authentication](https://firebase.google.com/docs/auth/web/password-auth) can be used for email address/password sign in. This sample specifically addresses the case in which an email address is not used as the unique identifier for a user.
 
-## Setup the sample
+## Set up the sample
 
-Create and setup the Firebase project:
+Create and set up the Firebase project:
  1. Create a Firebase project using the [Firebase Developer Console](https://console.firebase.google.com).
  1. Enable Billing on your Firebase project by switching to the **Blaze** plan, this is currently needed to be able to perform HTTP requests to external services from a Cloud Function.
- 1. Copy the Web initialisation snippet from **Firebase Console > Overview > Add Firebase to your web app** and paste it in `public/index.html` in lieu of the placeholder (where the `TODO(DEVELOPER)` is located).
+ 1. Copy the Web initialization snippet from **Firebase Console > Overview > Add Firebase to your web app** and paste it in `public/index.html` in lieu of the placeholder (where the `TODO(DEVELOPER)` is located).
 
 Create and provide a Service Account's credentials:
- 1. Create a Service Accounts file as described in the [Server SDK setup instructions](https://firebase.google.com/docs/server/setup#add_firebase_to_your_app).
- 1. Save the Service Account credential file as `./functions/service-account.json`
+ 1. Create a service account file as described in the [Server SDK setup instructions](https://firebase.google.com/docs/server/setup#add_firebase_to_your_app).
+ 1. Save the service account credential file as `./functions/service-account.json`
 
 Deploy your project:
  1. Run `firebase use --add` and choose your Firebase project. This will configure the Firebase CLI to use the correct project locally.
@@ -28,10 +28,10 @@ Enter credentials and click on the **Sign in** button. At this point you are aut
 
 ## Workflow and design
 
-When clicking the **Sign in** button the `auth` Cloud Function authenticates the username/password then Mints and returns a Firebase Custom Auth token (which is why we need Service Accounts Credentials).
+When clicking the **Sign in** button the `auth` Cloud Function authenticates the username/password then Mints and returns a Firebase Custom Auth token (which is why we need service accounts credentials).
 
 The [httpbin](https://httpbin.org) request & response service is used for the basic authentication request in this example.
 
-The main page will detect the sign-in through the Firebase Auth State observer and display the signed-In user information.
+The main page will detect the sign-in through the Firebase Auth State observer and display the signed-in user information.
 
 NOTE: In production you'll need to update the placeholder `authenticate` function in `./functions/index.js` so that it authenticates with your own credentials system.