HTTP API should include Data Type examples

[pjaclark]

The HTTP API does not include examples for Data Types: https://www.tiot.jp/riak-docs/riak/kv/3.2.0/developing/api/http/

For each operation, a Data Type example should be provided as well as a bucket and bucket type example.

[JMercerGit]

Additionally, the section on data types should link to this page rather than concepts https://www.tiot.jp/riak-docs/riak/kv/2.2.0/developing/data-types/