[PATCH v3] doc: improve e1000 driver documentation

[Talluri Chaitanyababu]

Update e1000 driver docs to cover all Intel 1G devices,
including emulated e1000 and real hardware.

v3: Resolved apply patch failure.

Signed-off-by: Talluri Chaitanyababu <chaitanyababux.talluri at intel.com>
---
 doc/guides/nics/e1000em.rst | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/doc/guides/nics/e1000em.rst b/doc/guides/nics/e1000em.rst
index ed4f57e9c6..c0fc4fe685 100644
--- a/doc/guides/nics/e1000em.rst
+++ b/doc/guides/nics/e1000em.rst
@@ -1,6 +1,22 @@
 ..  SPDX-License-Identifier: BSD-3-Clause
     Copyright(c) 2010-2014 Intel Corporation.
 
+E1000 Poll Mode Driver
+======================
+
+Overview
+--------
+
+DPDK provides several poll mode drivers (PMDs) supporting Intel 1 Gigabit ethernet controller families.
+These include:
+
+*   e1000 – Intel 8254x family devices, including QEMU ``e1000`` emulation.
+*   e1000e – Intel PRO/1000 PCI‑Express family (82563/6/7, 82571/2/3/4/7/8/9, 82583 and I217/I218/I219-based adapters).
+
+.. note::
+
+   The ``igb`` and ``igc`` PMDs are built from the same driver binary but are documented in separate sections for clarity.
+
 Driver for VM Emulated Devices
 ==============================
 
-- 
2.43.0