Clarify immich-admin command usage (#3456)

Some parts of the documentation state that administrative tasks like changing the admin password can be done via the `immich` function, but that is incorrect; instead, the `immich-admin` function should be used.

docs/docs/administration/server-commands.md

@@ -12,10 +12,12 @@ The `immich-server` docker image comes preinstalled with an administrative CLI (
 
 ## How to run a command
 
-To run a command, [connect](/docs/guides/docker-help.md#attach-to-a-container) to the `immich_server` container and then execute the command via `immich <command>`.
+To run a command, [connect](/docs/guides/docker-help.md#attach-to-a-container) to the `immich_server` container and then execute the command via `immich-admin <command>`.
 
 ## Examples
 
+Note that the commands below should begin with `immich-admin`.
+
 Reset Admin Password
 
 ![Reset Admin Password](./img/reset-admin-password.png)