Revert "Remove SSH console startup instructions"

This reverts commit ec56d20b3e.

src/admin_ssh_console.c

@@ -660,6 +660,8 @@ static void uart_frontend_task(void *context)
     (void)context;
     setvbuf(stdin, NULL, _IONBF, 0);
     linenoiseSetMaxLineLen(ADMIN_SSH_CONSOLE_COMMAND_LINE_CAPACITY);
+    printf("\r\nType 'help' to get the list of commands.\r\n"
+           "Use UP/DOWN arrows for history and TAB for completion.\r\n");
 
     for (;;) {
         char *line = linenoise("serial-tool> ");