Add missing files for the dist make target

Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>

Makefile.am

@@ -1,6 +1,13 @@
 SUBDIRS = src po
 
-man_MANS = man/axel.1
+dist_man_MANS = man/axel.1
+
+EXTRA_DIST = \
+	CONTRIBUTING.md \
+	CREDITS \
+	doc/axelrc.example \
+	man/axel.txt \
+	man/generate-man.sh
 
 distclean-local:
 	-rm -rf autom4te.cache/ \

src/Makefile.am

@@ -1,5 +1,22 @@
 bin_PROGRAMS = axel
-axel_SOURCES = axel.c conf.c conn.c ftp.c http.c search.c ssl.c tcp.c text.c
+axel_SOURCES = \
+	axel.c \
+	axel.h \
+	conf.c \
+	conf.h \
+	conn.c \
+	conn.h \
+	ftp.c \
+	ftp.h \
+	http.c \
+	http.h \
+	search.c \
+	search.h \
+	ssl.c \
+	ssl.h \
+	tcp.c \
+	tcp.h \
+	text.c
 
 AM_CPPFLAGS = -DLOCALEDIR=\""$(localedir)"\"
 AM_CPPFLAGS += -D_BSD_SOURCE -D_DEFAULT_SOURCE