adding fold param to /conversation api (#222)

src/v2/spec.yaml

@@ -4500,6 +4500,15 @@ paths:
           description: Sort type for the ordering of descendants. Default is `desc_chron`
           schema:
             $ref: "#/components/schemas/CastConversationSortType"
+        - name: fold
+          in: query
+          required: false
+          description: Show conversation above or below the fold. Lower quality responses are hidden below the fold. Not passing in a value shows the full conversation without any folding.
+          schema:
+            type: string
+            enum:
+              - above
+              - below
         - name: limit
           in: query
           description: Number of results to retrieve (default 20, max 50)