docs for audit logging
enterprise only note
enterprise page audit blurb
add audit to sidebar
add general options audit info
fix name for docs-navigation
link to docs
more docs
add audit log entry examples
fix audit link
clean up audit log docs
Includes:
* changes `nomad alloc status` and `nomad node status`
* changes to `volume` block in jobspec
* new `csi_plugin` block in jobspec
* new `nomad volume register/deregister/status` commands
* new `nomad plugin status` command
