nyx-lib: Add explanation why nyx-modules pulled in by packagegroup

* PR intentionally not incremented

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: If1f3b5abd1a03641ef0bc59633695d71f2ad65bb
Reviewed-on: https://g2g.palm.com/2130
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>