doc/cephadm: Clarify "Deploying a new Cluster"

Change the title of the section "Deploying a new Ceph cluster" to "Using
cephadm to Deploy a New Ceph Cluster". This is part of the initiative to
separate package-related documentation from container-based
documenation.

Signed-off-by: Zac Dover <[email protected]>

Author: zdover23

doc/cephadm/install.rst

@@ -1,8 +1,8 @@
 .. _cephadm_deploying_new_cluster:
 
-============================
-Deploying a new Ceph cluster
-============================
+==========================================
+Using cephadm to Deploy a New Ceph Cluster
+==========================================
 
 Cephadm creates a new Ceph cluster by bootstrapping a single
 host, expanding the cluster to encompass any additional hosts, and