[docs] Add missing top-level config key
The code-block for crowding_penalty was correct, but we were missing
the parent key.
@@ -652,9 +652,15 @@ warn_about_duplicates
- default: ``true``
+priorities
+----------
+
+- type: object
+- description: Configures how proximities are calculated, which is used by subsampling schemes which specify it.
+
crowding_penalty
-----------------
+~~~~~~~~~~~~~~~~
- type: float
- description: used when calculating ``priority scores`` during subsampling to decrease the number of identical samples that are included in the tree during random subsampling to provide a broader picture of the viral diversity in your dataset.
