config.mk: add comments for OpenBSD users

Closes: https://github.com/nsxiv/nsxiv/issues/262

Makefile

@@ -13,7 +13,7 @@ lib_gif_1 = -lgif
 lib_webp_0 =
 lib_webp_1 = -lwebpdemux -lwebp
 
-CPPFLAGS = -D_XOPEN_SOURCE=700 \
+CPPFLAGS = -D_XOPEN_SOURCE=700 $(INCLUDES) \
   -DHAVE_LIBGIF=$(HAVE_LIBGIF) -DHAVE_LIBEXIF=$(HAVE_LIBEXIF) \
   -DHAVE_LIBWEBP=$(HAVE_LIBWEBP) -DHAVE_LIBFONTS=$(HAVE_LIBFONTS) \
   -DHAVE_INOTIFY=$(HAVE_INOTIFY) $(inc_fonts_$(HAVE_LIBFONTS))

config.mk

@@ -23,3 +23,12 @@ CFLAGS = -std=c99 -Wall -pedantic
 
 # icons that will be installed via `make icon`
 ICONS = 16x16.png 32x32.png 48x48.png 64x64.png 128x128.png
+
+# Uncomment on OpenBSD
+# HAVE_INOTIFY = 0
+# lib_fonts_bsd_0 =
+# lib_fonts_bsd_1 = -lfreetype
+# inc_fonts_bsd_0 =
+# inc_fonts_bsd_1 = -I/usr/X11R6/include/freetype2
+# LDLIBS = -lz -L/usr/local/lib -L/usr/X11R6/lib $(lib_fonts_bsd_$(HAVE_LIBFONTS))
+# INCLUDES = -I/usr/local/include -I/usr/X11R6/include $(inc_fonts_bsd_$(HAVE_LIBFONTS))