Update README.md

Author: mckaragoz

README.md

@@ -19,8 +19,22 @@ Welcome to all contributors!
 
 ## Usage
 ### Preliminary: Set your google account and your project credentials
-Nothing special with this package.
-### Step 1: Inject HttpClientFactory
+Set your google client. This process has no special thing with this library. [Read the details.](https://developers.google.com/identity/gsi/web/guides/get-google-api-clientid)
+<br /> Add the credential into appsettings.json file like the below example. (Not obligatory, but ClientId, ClientSecret and RedirectUrl is required for some features to use this library simpler.)
+```json
+{
+  "GoogleClient": {
+    "client_id": "[CLIENT_ID]",
+    "project_id": "",
+    "auth_uri": "",
+    "token_uri": "",
+    "auth_provider_x509_cert_url": "",
+    "client_secret": "[CLIENT_SECRET]",
+    "redirect_url": "[REDIRECT_URL]"
+  }
+}
+```
+### Step 1: Inject Services
 
 Add Services into program.cs
 ```cs
@@ -29,10 +43,12 @@ builder.Services.AddCodeBeamGoogleApiServices();
 
 For blazor component files
 ```razor
+@inject AuthService AuthService
 @inject CalendarService CalendarService
 ```
-For cs files
+OR - For cs files
 ```cs
+[Inject] AuthService AuthService { get; set; }
 [Inject] CalendarService CalendarService { get; set; }
 ```
 
@@ -66,7 +82,7 @@ private async Task RequestCode()
 ```
 #### Step 2. Get Access Token With Obtained Authorization Code in Step 1
 These codes should be in the callback page.
-Blazor Component
+<br /> Blazor Component
 ```razor
 @page "/v1/browser-callback"
 ```
@@ -108,3 +124,19 @@ private void AddEvent()
     string result = CalendarService.AddEvent(googleCalendarEvent, CalendarService.FindCalendarId(CalendarValueType.Summary, "Test Calendar"));
 }
 ```
+
+## How To Get and Process Lists (Like Calendar and Event)
+When you call the api to return a list of items (like calendars or events) it returns a root class. These classes can be find in the library. You can use the "items" property to reach list of items.
+<br />
+<br />
+#### The Models
+- GoogleCalendarListRoot -> The root calendar model which is a proper for `GetCalendars()` method result
+- GoogleCalendarListModel -> The calendar model. GoogleCalendarListRoot.items has a `List<GoogleCalendarListModel>`
+- GoogleCalendarEventRoot -> The root event model which is a proper for `GetEvents()` method result
+- GoogleCalendarEventModel -> The event model. GoogleCalendarEventRoot.items has a `List<GoogleCalendarEventModel>`
+
+#### Usage
+```cs
+var result = CalendarService.GetCalendars();
+GoogleCalendarListRoot _calendars = JsonSerializer.Deserialize<GoogleCalendarListRoot>(result); // _calendars.items has the list of calendars.
+```