CREDITS: Add entry for Shannon Nelson

I'm retiring and have already had my name removed from MAINTAINERS.
A couple of folks kindly suggested I should have an entry here.

Signed-off-by: Shannon Nelson <sln@onemain.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250619211607.1244217-1-sln@onemain.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: emusln

CREDITS

@@ -2981,6 +2981,11 @@ S: 521 Pleasant Valley Road
 S: Potsdam, New York 13676
 S: USA
 
+N: Shannon Nelson
+E: sln@onemain.com
+D: Worked on several network drivers including
+D: ixgbe, i40e, ionic, pds_core, pds_vdpa, pds_fwctl
+
 N: Dave Neuer
 E: dave.neuer@pobox.com
 D: Helped implement support for Compaq's H31xx series iPAQs