[docs] move Cache/Alluxio into Connectors/Hive doc

Because caching is connector-specific, the Presto documentation should include caching docs in the appropriate connector documentation. Recommend moving the content in Cache into or underneath Hive Connector docs.

Expected Behavior or Use Case

Caching documentation should be located where it is most valuable. Because caching is connector-specific, this should be in the Connectors part of presto-docs.

Presto Component, Service, or Connector

Presto documentation.

Possible Implementation

Instead of moving the content into the single Hive Connector page, perhaps create a new page "Hive Cache" in /connectors and add it to Connectors, directly under Hive Security Configuration.

Example Screenshots (if appropriate):

Context

Improving the Presto docs architecture by moving content to where it is relevant.