Update docs

Author: JE-Chen

docs/source/docs/API/api_index.rst

@@ -4,17 +4,6 @@ API Reference
 This section provides the complete API reference for all public classes, methods,
 and functions in MailThunder.
 
-.. toctree::
-   :maxdepth: 3
-   :caption: API Documentation
-
-   smtp_api
-   imap_api
-   executor_api
-   utils_api
-
-----
-
 Public Exports
 --------------
 

docs/source/index.rst

@@ -75,7 +75,7 @@ Quick Example
 ----
 
 .. toctree::
-   :maxdepth: 3
+   :maxdepth: 4
    :caption: English Documentation
 
    docs/Eng/eng_index
@@ -92,7 +92,7 @@ Quick Example
    docs/Eng/exceptions
 
 .. toctree::
-   :maxdepth: 3
+   :maxdepth: 4
    :caption: 繁體中文文件
 
    docs/Zh/zh_index
@@ -109,7 +109,7 @@ Quick Example
    docs/Zh/exceptions
 
 .. toctree::
-   :maxdepth: 3
+   :maxdepth: 4
    :caption: API Reference
 
    docs/API/api_index