Added ntp doc

docs/alpine-desktop-setup/installation/installation.md

@@ -31,6 +31,7 @@ The other "setup" scripts can be used to configure key aspects of the system.
 # setup-hostname <hostname>
 # setup-keymap us us-euro
 # setup-timezone -i <Area>/<Subarea>
+# setup-chrony chrony
 # rc-update add acpid default
 # passwd root
 ```

mkdocs.yml

@@ -38,7 +38,6 @@ nav:
       - 'Nix': alpine-desktop-setup/post-install/nix.md
       - 'Config files': alpine-desktop-setup/post-install/config-files.md
       - 'Network': alpine-desktop-setup/post-install/network.md
-      - 'Date and time': alpine-desktop-setup/post-install/time.md
       - 'Zram': alpine-desktop-setup/post-install/zram.md
       - 'OpenRC': alpine-desktop-setup/post-install/openrc.md
       - 'Firmware and drivers': alpine-desktop-setup/post-install/drivers.md