Ports: Add nnn port

This ports the nnn (n³ / Nnn's Not Noice) file manager.

Ports/nnn/patches/0002-Link-with-fts-library.patch

@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Rene Hickersberger <r@renehsz.com>
+Date: Sat, 24 Jun 2023 01:17:30 +0200
+Subject: [PATCH] Link with fts library
+
+Nnn depends on the non-standard fts functions to traverse the file
+system. Most BSD systems provide them out of the box and on
+GNU/Linux systems, they are part of glibc.
+
+On Serenity, they are provided by a separate library (the libfts port)
+that was originally intended for musl-based Linux systems.
+This patch makes nnn link against this library.
+---
+ Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makefile b/Makefile
+index b6930330be77f9f2f252a96ba9b3e727ddfdc5aa..955965aad67967a5acd73822647b2ce11d4a819e 100644
+--- a/Makefile
++++ b/Makefile
+@@ -59,7 +59,7 @@ ifeq ($(strip $(O_NORL)),1)
+ else ifeq ($(strip $(O_STATIC)),1)
+ 	CPPFLAGS += -DNORL
+ else
+-	LDLIBS += -lreadline
++	LDLIBS += -lreadline -lfts
+ endif
+ 
+ ifeq ($(strip $(O_PCRE)),1)