docs: restructure and enhance documentation for Ads and Anonymous Numbers features

docs/client/anonymous-numbers/get-login-code.md

@@ -0,0 +1,19 @@
+# Get Login Code
+
+Use this method to fetch a pending login code for an anonymous number.
+
+## Method
+
+```python
+await client.get_login_code(number: str) -> LoginCodeResult
+```
+
+## Parameters
+
+- `number`: anonymous number (with or without leading `+`)
+
+## Return
+
+- `number`
+- `code` (`None` if no pending code)
+- `active_sessions`