DOC-13883: Replace references to lock-admin with admin-manage

Originally the documentation was written as lock-admin and unlock-admin
being separate commands, but this was changed to just use a single
admin-manage command. In a couple places the old "lock-admin" was left
behind, which should just be replaced with "admin-manage".

Change-Id: I069e4f9d8053f5a883f98d76ff6ed9eb5d16a025
Reviewed-on: https://review.couchbase.org/c/couchbase-cli/+/238213
Well-Formed: Restriction Checker
Reviewed-by: Matt Hall <matt.hall@couchbase.com>
Tested-by: Build Bot <build@couchbase.com>

Author: Peter-Searby

docs/modules/cli/pages/_partials/cbcli/nav.adoc

@@ -1,5 +1,5 @@
 * xref:cli:cbcli/couchbase-cli.adoc[couchbase-cli]
- ** xref:cli:cbcli/couchbase-cli-admin-manage.adoc[lock-admin]
+ ** xref:cli:cbcli/couchbase-cli-admin-manage.adoc[admin-manage]
  ** xref:cli:cbcli/couchbase-cli-analytics-link-setup.adoc[analytics-link-setup]
  ** xref:cli:cbcli/couchbase-cli-backup-service.adoc[backup-service]
  ** xref:cli:cbcli/couchbase-cli-backup-service-nodes-threads-map.adoc[backup-service nodes-threads-map]

docs/modules/cli/pages/cbcli/couchbase-cli-admin-manage.adoc

@@ -1,4 +1,4 @@
-= couchbase-cli-lock-admin(1)
+= couchbase-cli-admin-manage(1)
 :description: Manages the built-in Couchbase Server administrator
 ifndef::doctype-manpage[:doctitle: admin-manage]