Ports: Add groff

This port is exceptionally useful in the ports ecosystem, as it will
allow us to read ROFF manual pages within the system.

Ports/groff/patches/0001-Include-config.h-in-math.h.patch

@@ -0,0 +1,23 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Liav A <liavalb@gmail.com>
+Date: Sat, 12 Aug 2023 19:14:23 +0300
+Subject: [PATCH] Include config.h in math.h
+
+Otherwise the build will fail due to #define(s) not being included.
+---
+ lib/math.in.h | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/lib/math.in.h b/lib/math.in.h
+index c30fc202c0d31b7df331a9910dae0842511589ba..2b595710530c99ec4f4a6681e4e2b623716028d1 100644
+--- a/lib/math.in.h
++++ b/lib/math.in.h
+@@ -33,6 +33,8 @@
+ # include <fp.h>
+ #endif
+ 
++#include <config.h>
++
+ #ifndef _GL_INLINE_HEADER_BEGIN
+  #error "Please include config.h first."
+ #endif