Clarify the use of the dedicated pool

Signed-off-by: Benoit Donneaux <benoit@leastauthority.com>

morph/grid/local/README.rst

@@ -21,15 +21,18 @@ Setup virtualisation on the host
     # Enable HW acceleration if (nested virtualisation is) available
     #boot.kernelModules = [ "kvm-amd" "kvm-intel" ];
 
-2. Create a dedicated pool (optional - to avoid `/var/lib/libvirt/storage`)::
+2. OPTIONAL - Create a dedicated pool only to avoid the default in ``/var/lib/libvirt/storage``)::
 
-    export POOL_NAME=morph_local
-    POOL_PATH="~/.libvirt/images"
+    export POOL_NAME=morph_local_$(id -un)
+    POOL_PATH="/path/to/your/storage"
     mkdir -p "${POOL_PATH}"
     sudo virsh pool-define-as ${POOL_NAME} --type dir --target "${POOL_PATH}"
     sudo virsh pool-autostart ${POOL_NAME}
     sudo virsh pool-start ${POOL_NAME}
 
+   REM:
+   - The files generated in the next steps in ``POOL_PATH`` will be owned by root.
+   - Do not forget the ``POOL_NAME`` variable exported above for the next steps.
 
 Use the local development environment
 `````````````````````````````````````