Add tag for OS identifier

For Developers
1

I compile normal and i have this:
OpenWrt 19.07-SNAPSHOT r11267-b14eeccdfe

if i add one tag, example: opennds
OpenWrt 19.07-SNAPSHOT r11267-b14eeccdfe - opennds

i see this: https://github.com/openwrt/openwrt/blob/master/include/version.mk
if fork repo howto edit version.mk for add tag?
or edit .config?

I compile for multi device and multi configuration and using jenkins+ansible with this:

thanks.