Added the API definition for `bulk`

rest-api-spec/api/bulk.json

@@ -7,23 +7,42 @@
       "paths": ["/_bulk", "/{index}/_bulk", "/{index}/{type}/_bulk"],
       "parts": {
         "index": {
+          "type" : "string",
+          "description" : "Default index for items which don't provide one"
         },
         "type": {
+          "type" : "string",
+          "description" : "Default document type for items which don't provide one"
         }
       },
       "params": {
         "consistency": {
+          "type" : "enum",
+          "options" : ["one", "quorum", "all"],
+          "description" : "Explicit write consistency setting for the operation"
         },
         "index": {
+          "type" : "string",
+          "description" : "Default index for items which don't provide one"
         },
         "refresh": {
+          "type" : "boolean",
+          "description" : "Refresh the index after performing the operation"
         },
         "replication": {
+          "type" : "enum",
+          "options" : ["sync","async"],
+          "default" : "sync",
+          "description" : "Explicitely set the replication type"
         },
         "type": {
+          "type" : "string",
+          "description" : "Default document type for items which don't provide one"
         }
       }
     },
-    "body": null
+    "body": {
+      "description" : "The operation definition and data (action-data pairs), separated by newlines"
+    }
   }
 }