Port markdown docs to rst and introduce "githublink" (#3107)

docs/en_US/TrainingService/AdaptDLMode.md → docs/archive_en_US/TrainingService/AdaptDLMode.md

@@ -66,7 +66,7 @@ trial:
     path: /
     containerMountPath: /nfs
   checkpoint: # optional
-    storageClass: dfs
+    storageClass: microk8s-hostpath
     storageSize: 1Gi
 ```
 
@@ -90,10 +90,7 @@ IP address of the machine with NNI manager (NNICTL) that launches NNI experiment
     * **memorySize**: (*Optional*) the size of memory requested for this trial. It must follow the Kubernetes
     [default format](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memory).
     * **nfs**: (*Optional*) mounting external storage. For more information about using NFS please check the below paragraph.
-  * **checkpoint**: (*Optional*) storage settings for model checkpoints.
-    * **storageClass**: check [Kubernetes storage documentation](https://kubernetes.io/docs/concepts/storage/storage-classes/) for how to use the appropriate `storageClass`.
-    * **storageSize**: this value should be large enough to fit your model's checkpoints, or it could cause disk quota exceeded error.
-
+    * **checkpoint** (*Optional*) [storage settings](https://kubernetes.io/docs/concepts/storage/storage-classes/) for AdaptDL internal checkpoints. You can keep it optional if you are not dev users.
 
 ### NFS Storage