docs (Microsoft Auth): Add docs regarding whitelist system (#300)

* docs (Microsoft Auth): Add docs regarding whitelist system

* docs: Commit Dan's suggestion

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

* docs: Commit Dan's second suggestion

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

* docs: Commit Dan's third suggestion

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

* docs: Commit Dan's fourth suggestion

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

* docs: Commit Dan's fifth suggestion

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

---------

Co-authored-by: Daniel Scalzi <d_scalzi@yahoo.com>

docs/MicrosoftAuth.md

@@ -18,18 +18,35 @@ Authenticating with Microsoft is fully supported by Helios Launcher.
     - Select **Mobile and desktop applications**.
     - Choose `https://login.microsoftonline.com/common/oauth2/nativeclient` as the **Redirect URI**.
     - Select **Configure** to finish adding the platform.
+8. Go to **Credentials & secrets**.
+    - Select **Client secrets**.
+    - Click **New client secret**.
+    - Set a description.
+    - Click **Add**.
+    - Don't copy the client secret, adding one is just a requirement from Microsoft.
 8. Navigate back to **Overview**.
 9. Copy **Application (client) ID**.
 
 
-Reference: https://docs.microsoft.com/en-us/azure/active-directory/develop/quickstart-register-app
-
 ## Adding the Azure Client ID to Helios Launcher.
 
 In `app/assets/js/ipcconstants.js` you'll find **`AZURE_CLIENT_ID`**. Set it to your application's id.
 
 Note: Azure Client ID is NOT a secret value and **can** be stored in git. Reference: https://stackoverflow.com/questions/57306964/are-azure-active-directorys-tenantid-and-clientid-considered-secrets
 
+Then relaunch your app, and login. You'll be greeted with an error message, because the app isn't whitelisted yet. Microsoft needs some activity on the app before whitelisting it. __Trying to log in before requesting whitelist is mandatory.__
+
+## Requesting whitelisting from Microsoft
+
+1. Ensure you have completed every step of this doc page.
+2. Fill [this form](https://aka.ms/mce-reviewappid) with the required information. Remember this is a new appID for approval. You can find both the Client ID and the Tenant ID on the overview page in the Azure Portal.
+3. Give Microsoft some time to review your app.
+4. Once you have received Microsoft's approval, allow up to 24 hours for the changes to apply.
+
 ----
 
-You can now authenticate with Microsoft through the launcher.
+You can now authenticate with Microsoft through the launcher.
+
+References:
+- https://docs.microsoft.com/en-us/azure/active-directory/develop/quickstart-register-app
+- https://help.minecraft.net/hc/en-us/articles/16254801392141