Fix random behavior of update_model_index in pre-commit hook (open-mmlab#866)

* Add require_serial to prevent multi-threading that causes file I/O conflict
* Modify update_model_index.py to prevent redundant file I/O
* Set sort_keys=True and update model .yml files

Author: ly015

.pre-commit-config.yaml

@@ -48,3 +48,4 @@ repos:
         additional_dependencies: [mmcv]
         language: python
         files: ^configs/.*\.md$
+        require_serial: true

configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_animalpose.yml

@@ -1,40 +1,40 @@
 Collections:
-- Name: hrnet_animalpose
-  Metadata:
+- Metadata:
     Architecture:
     - HRNet
-  README: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_animalpose.md
+  Name: hrnet_animalpose
   Paper:
   - http://openaccess.thecvf.com/content_CVPR_2019/html/Sun_Deep_High-Resolution_Representation_Learning_for_Human_Pose_Estimation_CVPR_2019_paper.html
   - http://openaccess.thecvf.com/content_ICCV_2019/html/Cao_Cross-Domain_Adaptation_for_Animal_Pose_Estimation_ICCV_2019_paper.html
+  README: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_animalpose.md
 Models:
-- Name: animal--2d_kpt_sview_rgb_img--topdown_heatmap--animalpose--hrnet_w32_animalpose_256x256
+- Config: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_w32_animalpose_256x256.py
   In Collection: hrnet_animalpose
-  Config: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_w32_animalpose_256x256.py
   Metadata:
     Training Data: Animal-Pose
+  Name: animal--2d_kpt_sview_rgb_img--topdown_heatmap--animalpose--hrnet_w32_animalpose_256x256
   Results:
-  - Task: 2D Animal Keypoint Detection
-    Dataset: Animal-Pose
+  - Dataset: Animal-Pose
     Metrics:
       AP: 0.736
       AP@0.5: 0.959
       AP@0.75: 0.832
       AR: 0.775
       AR@0.5: 0.966
+    Task: 2D Animal Keypoint Detection
   Weights: https://download.openmmlab.com/mmpose/animal/hrnet/hrnet_w32_animalpose_256x256-1aa7f075_20210426.pth
-- Name: animal--2d_kpt_sview_rgb_img--topdown_heatmap--animalpose--hrnet_w48_animalpose_256x256
+- Config: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_w48_animalpose_256x256.py
   In Collection: hrnet_animalpose
-  Config: configs/animal/2d_kpt_sview_rgb_img/topdown_heatmap/animalpose/hrnet_w48_animalpose_256x256.py
   Metadata:
     Training Data: Animal-Pose
+  Name: animal--2d_kpt_sview_rgb_img--topdown_heatmap--animalpose--hrnet_w48_animalpose_256x256
   Results:
-  - Task: 2D Animal Keypoint Detection
-    Dataset: Animal-Pose
+  - Dataset: Animal-Pose
     Metrics:
       AP: 0.737
       AP@0.5: 0.959
       AP@0.75: 0.823
       AR: 0.778
       AR@0.5: 0.962
+    Task: 2D Animal Keypoint Detection
   Weights: https://download.openmmlab.com/mmpose/animal/hrnet/hrnet_w48_animalpose_256x256-34644726_20210426.pth