fix: remove outdated files

Author: Sibo2rr

docs/en/advanced_tutorials/index.rst

@@ -2,7 +2,7 @@ advanced_tutorials
 ================================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    DataAugmentation_en.md
    distillation/index

docs/en/algorithm_introduction/index.rst

@@ -2,7 +2,7 @@ algorithm_introduction
 ================================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    image_classification_en.md
    metric_learning_en.md

docs/en/data_preparation/index.rst

@@ -2,7 +2,7 @@ data_preparation
 ================================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    recognition_dataset_en.md
    classification_dataset_en.md

docs/en/doc_en.rst

@@ -15,7 +15,6 @@ Welcome to PaddleClas！
    algorithm_introduction/index
    advanced_tutorials/index
    others/index
-   extension/index
    faq_series/index
 
 

docs/en/extension/VisualDL_en.md

@@ -2,7 +2,7 @@ faq_series
 ================================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    faq_2021_s2_en.md
    faq_2021_s1_en.md

docs/en/extension/index.rst

@@ -2,7 +2,7 @@ image_recognition_pipeline
 ================================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    mainbody_detection_en.md
    feature_extraction_en.md

docs/en/extension/multi_machine_training_en.md

@@ -5,7 +5,6 @@
    :maxdepth: 2
 
    models_training/index
-   extension/index
    introduction/index
    image_recognition_pipeline/index
    others/index