documentation, adding google configuration notes

docs/config-google.md

@@ -17,7 +17,47 @@ It will take a moment for Google to create your new project. Once it has been cr
 
 * Select **Credentials**, in the left sidebar, and then select the **OAuth consent screen** tab.
 
+* Enter the **Product name** that will be shown to your users, when the login using Google.
+
 ![Google OAuth consent screen](./images/google-oauth-consent.png)
 
+* Click **Save**
 
-### Step 2
+* Enable the Google+ API, select **Overview** in the left nav, and choose the **Google+ API**, from the the list of Social APIs.
+
+![Google+ API](./images/google-plus-api.png)
+
+* Click **Enable**
+
+* Select **Credentials**, in the left sidebar, click on **Create credentials** and select **OAuth client ID** from the pop-up list.
+
+![Google Select OAuth client ID](./images/google-oauth-client-select.png)
+
+* Select **Web application**, and provide a name for your web application.
+
+  * **Authorized JavaScript Origins**: `http://example.wiki`
+  * **Authorized redirect URI**: `http://example.wiki/auth/google/callback`
+
+  Replacing `example.wiki` with your wiki server root domain, also replacing `http` with `https` if you are using https *you can also enter both to support to ease migration*. If your wiki server is supporting multiple wiki domains, you can enter them as well.
+
+![Google Create OAuth client ID](./images/google-oauth-client-create.png)
+
+* Click **Create**. Your `Client ID` and `Client Secret` will be displayed, save these to use to configure your wiki in the next step.
+
+![Google OAuth Secrets](./images/google-oauth-secrets.png)
+
+### Configure Wiki
+
+The wiki is configured by adding the `client ID` and `client secret` to the configuration. They need not be added inside the `wikiDomains` definition, as the OAuth can have multiple callbacks defined, we still need the domain definition so that the wiki security plugin can understand what is required.
+
+```JSON
+{
+  "farm": true,
+  "security_type": "passportjs",
+  "google_clientID": "CLIENT ID",
+  "google_clientSecret": "CLIENT SECRET",
+  "wikiDomains": {
+    "example.wiki": {}
+  }
+}
+```