DOCS-13849 fix method definition to include args

Author: andf-mongodb

source/reference/method/db.collection.ensureIndex.txt

@@ -4,7 +4,7 @@ db.collection.ensureIndex()
 
 .. default-domain:: mongodb
 
-.. method:: db.collection.ensureIndex()
+.. method:: db.collection.ensureIndex(keys, options)
 
 .. admonition:: Removed in 5.0
    :class: note
@@ -14,4 +14,4 @@ db.collection.ensureIndex()
 
 .. seealso:: 
 
-   :method:`db.collection.createIndex()`
+   :method:`db.collection.createIndex()`