Rename es24n/ to modules/

Update sys.path reference in es24n_conf.py and all documentation
to reflect the new folder name.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

es24n_conf.py

@@ -10,7 +10,7 @@ Compatible with TrueNAS (FreeBSD) and Linux.
 Usage:
     python3 es24n_conf.py
 
-All files in the es24n/ subdirectory must be present:
+All files in the modules/ subdirectory must be present:
     ui.py, serial_port.py, models.py, redfish.py,
     workflow_serial.py, workflow_firmware.py
 """
@@ -19,7 +19,7 @@ import os
 import sys
 import time
 
-sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "es24n"))
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "modules"))
 
 from ui import _c, C, banner, draw_box, ok, warn, prompt
 from workflow_firmware import firmware_update_workflow