Add installation of man page

Makefile

@@ -16,21 +16,31 @@ SUBCOMMANDS = random \
 	      amngrrename \
 	      amngrsearch
 
-PREFIX ?= /usr/local
+PREFIX ?= /usr
+DESTDIR ?=
+
+export PREFIX DESTDIR
 
 PROGRAM := accountmanager.sh
 
-all:
+all: doc
+
+.PHONY: clean install doc
+
+doc:
+	make -C doc
 
-.PHONY: clean install
+install_doc: doc
+	make -C doc install
 
 install_$(PROGRAM):
-	@install "$(PROGRAM)" "$(DESTDIR)/$(PREFIX)/bin/$(PROGRAM)"
+	@install -D "$(PROGRAM)" "$(DESTDIR)/$(PREFIX)/bin/$(PROGRAM)"
 
 install_%:
 	@ln -s "$(realpath ${DESTDIR}/${PREFIX}/bin/$(PROGRAM))" \
 		"${DESTDIR}/$(PREFIX)/bin/$(subst install_,,$@)"
 
-install: install_$(PROGRAM) $(patsubst %,install_%,$(SUBCOMMANDS))
+install: install_$(PROGRAM) $(patsubst %,install_%,$(SUBCOMMANDS)) install_doc
 
 clean:
+	make -C doc clean

doc/Makefile

@@ -0,0 +1,14 @@
+all: doc
+
+accountmanager.1.bz2: accountmanager.1
+	bzip2 -c -9 $< >$@
+
+.PHONY: all clean install doc
+
+doc: accountmanager.1.bz2
+
+install: accountmanager.1.bz2
+	@install -D -m 0644 "$<" "$(DESTDIR)/$(PREFIX)/share/man/man1/$<"
+
+clean:
+	@rm -f accountmanager.1.bz2