sysutils/nnn: add -nerd flavor for usage with *-nerd-fonts

based on a diff from Joel Carnat (joel [at] carnat [dot] net) with the
DESCR wording from sthen@.  ok maintainer (Martin Ziemer)

sysutils/nnn/Makefile

@@ -3,6 +3,7 @@ COMMENT =		the missing terminal file browser for X
 V =			4.7
 DISTNAME =		nnn-v${V}
 PKGNAME =		nnn-${V}
+REVISION =		0
 
 CATEGORIES =		sysutils
 
@@ -27,6 +28,13 @@ MAKE_FLAGS =		CFLAGS_OPTIMIZATION=
 FAKE_FLAGS =		MANPREFIX="$(PREFIX)/man" \
 			PREFIX="${PREFIX}"
 
+FLAVORS =		nerd
+FLAVOR ?=
+
+.if ${FLAVOR:Mnerd}
+MAKE_FLAGS +=		O_NERD=1
+.endif
+
 USE_GMAKE =		Yes
 NO_TEST =		Yes
 

sysutils/nnn/pkg/DESCR

@@ -18,3 +18,8 @@ Cool things you can do with nnn:
 - pin a directory you may need to revisit and jump to it anytime
 - lock the current terminal after a specified idle time
 - change directory on exit
+
+Flavor: nerd
+    build with support for Nerd Fonts, requires a terminal emulator
+    configured to use a font from one of the *-nerd-fonts packages,
+    e.g. noto-nerd-fonts or others.