all: update to match GCK standard

doc/Makefile

@@ -0,0 +1,22 @@
+hello.info: hello.texi version.texi
+	makeinfo --no-split hello.texi -o hello.info
+
+hello.html: hello.texi version.texi
+	makeinfo --no-split --html hello.texi
+
+hello.pdf: hello.texi version.texi
+	makeinfo --pdf hello.texi
+
+hello.txt: hello.texi version.texi
+	makeinfo --plaintext hello.texi -o hello.txt
+
+clean:
+	rm -f *.aux *.cp *.cps *.fn *.fns *.ky *.kys *.log *.pg *.pgs *.toc *.tp *.tps *.vr *.vrs
+	rm -f hello.info hello.dvi hello.pdf hello.html hello.txt
+
+install: hello.info
+	install -d $(DESTDIR)$(infodir)
+	install -m 644 hello.info $(DESTDIR)$(infodir)/
+	install-info --info-dir=$(DESTDIR)$(infodir) $(DESTDIR)$(infodir)/hello.info
+
+.PHONY: all clean install