Added contacts list & GUI examples

EXAMPLES.md

@@ -191,6 +191,39 @@ for (int offset = 0; ;)
 }
 ```
 
+<a name="contacts"></a>
+### Retrieve the current user's contacts list
+There are two different methods. Here is the simpler one:
+```csharp
+using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
+await client.LoginUserIfNeeded();
+var contacts = await client.Contacts_GetContacts(0);
+foreach (User contact in contacts.users.Values)
+    Console.WriteLine($"{contact} {contact.phone}");
+```
+<a name="takeout"></a>
+The second method uses the more complex GDPR export, **takeout session** system.
+Here is an example on how to implement it:
+```csharp
+using TL.Methods; // methods structures, for InvokeWithTakeout
+
+using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
+await client.LoginUserIfNeeded();
+var takeout = await client.Account_InitTakeoutSession(contacts: true);
+var finishTakeout = new Account_FinishTakeoutSession();
+try
+{
+    var savedContacts = await client.InvokeWithTakeout(takeout.id, new Contacts_GetSaved());
+    foreach (SavedPhoneContact contact in savedContacts)
+        Console.WriteLine($"{contact.first_name} {contact.last_name} {contact.phone}, added on {contact.date}");
+    finishTakeout.flags = Account_FinishTakeoutSession.Flags.success;
+}
+finally
+{
+    await client.InvokeWithTakeout(takeout.id, finishTakeout);
+}
+```
+
 <a name="updates"></a>
 ### Monitor all Telegram events happening for the user
 

FAQ.md

@@ -34,7 +34,7 @@ An easy solution is to call `Interaction.InputBox("Enter verification code")` in
 This might require adding a reference *(and `using`)* to the Microsoft.VisualBasic assembly.
 
 A more complex solution requires the use of a `ManualResetEventSlim` that you will wait for in Config callback,
-and when the user has provided the verification_code through your GUI, you "set" the event to release your Config callback so it can return the code.
+and when the user has provided the verification_code through your GUI, you "set" the event to release your Config callback so it can return the code. ([see example](https://stackoverflow.com/a/70379582/3365403))
 
 <a name="access-hash"></a>
 #### 4. Where to get the access_hash? Why the error `CHANNEL_INVALID` or `USER_ID_INVALID`?

README.md

@@ -10,7 +10,7 @@
 # How to use
 
 >⚠️ This library relies on asynchronous C# programming (`async/await`) so make sure you are familiar with this advanced topic before proceeding.  
->If you are a beginner in C#, making a project based on this library might not be a great idea.
+>If you are a beginner in C#, starting a project based on this library might not be a great idea.
 
 After installing WTelegramClient through Nuget, your first Console program will be as simple as:
 ```csharp