Integrate Store Object in HTTP API overview

The `HTTP Store Object` page lists `POST .../keys` and `PUT
.../keys/key` explicitly and in this order, then `POST .../keys/key`
implicitly. Make the HTTP API overview page consistent with that.

Author: Luca Favatella

Diff for: content/riak/kv/2.2.0/developing/api/http.md

@@ -40,8 +40,9 @@ Method | URL | Doc
 Method | URL | Doc
 :------|:----|:---
 `GET` | `/types/<type>/buckets/<bucket>/keys/<key>` | [HTTP Fetch Object](/riak/kv/2.2.0/developing/api/http/fetch-object)
-`POST` | `/types/<type>/buckets/<bucket>/keys/<key>` | [HTTP Store Object](/riak/kv/2.2.0/developing/api/http/store-object)
+`POST` | `/types/<type>/buckets/<bucket>/keys` | [HTTP Store Object](/riak/kv/2.2.0/developing/api/http/store-object)
 `PUT` | `/types/<type>/buckets/<bucket>/keys/<key>` | [HTTP Store Object](/riak/kv/2.2.0/developing/api/http/store-object)
+`POST` | `/types/<type>/buckets/<bucket>/keys/<key>` | [HTTP Store Object](/riak/kv/2.2.0/developing/api/http/store-object)
 `DELETE` | `/types/<type>/buckets/<bucket>/keys/<key>` | [HTTP Delete Object](/riak/kv/2.2.0/developing/api/http/delete-object)
 
 ## Riak-Data-Type-related Operations