Added the API definition for creating the index

rest-api-spec/api/indices.create.json

@@ -1,22 +1,30 @@
 {
   "indices.create": {
-    "documentation": "http://elasticsearch.org/guide/reference/mapping/",
+    "documentation": "http://www.elasticsearch.org/guide/reference/api/admin-indices-create-index/",
     "methods": ["PUT", "POST"],
     "url": {
       "path": "/{index}",
       "paths": ["/{index}"],
       "parts": {
         "index": {
+          "type" : "string",
+          "required" : true,
+          "description" : "The name of the index"
         }
       },
       "params": {
         "index": {
+          "type" : "string",
+          "description" : "The name of the index"
         },
         "timeout": {
+          "type" : "time",
+          "description" : "Explicit operation timeout"
         }
       }
     },
     "body": {
+      "description" : "The configuration for the index (`settings` and `mappings`)"
     }
   }
 }