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

Ports/groff/patches/0002-Don-t-redeclare-signbit-function.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 19:15:27 +0300
+Subject: [PATCH] Don't redeclare signbit function
+
+We have it already implemented so simply use what we have.
+---
+ lib/math.in.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/math.in.h b/lib/math.in.h
+index 2b595710530c99ec4f4a6681e4e2b623716028d1..419ab4a609ce0ecd753bb9673819144d81836d8b 100644
+--- a/lib/math.in.h
++++ b/lib/math.in.h
+@@ -2344,7 +2344,7 @@ _GL_WARN_REAL_FLOATING_DECL (isnan);
+ #endif
+ 
+ 
+-#if @GNULIB_SIGNBIT@
++#if 0
+ # if (@REPLACE_SIGNBIT_USING_GCC@ \
+       && (!defined __cplusplus || __cplusplus < 201103))
+ #  undef signbit

Ports/groff/patches/ReadMe.md

@@ -0,0 +1,14 @@
+# Patches for groff on SerenityOS
+
+## `0001-Include-config.h-in-math.h.patch`
+
+Include config.h in math.h
+
+Otherwise the build will fail due to #define(s) not being included.
+
+## `0002-Don-t-redeclare-signbit-function.patch`
+
+Don't redeclare signbit function
+
+We have it already implemented so simply use what we have.
+