Create Couchbase Shell Guide for Query

Create a guide to using Couchbase Shell for the Query Service. This should aim to cover most of the material in the cbq documentation for Query.

There's no need to cover connection and authentication in detail, as this is already covered by the Connect guides and the CB shell documentation. But this guide should cover:

• Starting and exiting Couchbase shell
• Running queries with the Query command
• Formatting the results through to json
• Getting metrics
• Setting the query context
• Setting aliases for frequently-used commands
• Setting and checking the value of variables in Couchbase shell
• File based operations
• When available, setting query parameters
• Getting the version of Couchbase shell