Add a Makefile to build XEPs

Makefile

@@ -0,0 +1,32 @@
+.SILENT:
+
+OUTDIR?=build
+XMLDEPS=xep.xsl xep.xsd xep.ent xep.dtd ref.xsl
+
+.PHONY: help
+help:
+	@echo 'XEP makefile targets:'
+	@echo ' '
+	@echo '                  help  -  (this message)'
+	@echo '                   all  -  build all XEPs'
+	@echo '                 clean  -  recursively unlink the build tree'
+	@echo '              xep-xxxx  -  build xep-xxxx.html'
+	@echo ' '
+	@echo 'Output directory: "$(OUTDIR)/"'
+
+.PHONY: all
+all: $(patsubst %.xml, $(OUTDIR)/%.html, $(wildcard *.xml))
+
+.PHONY: xep-%
+xep-%: $(OUTDIR)/xep-%.html
+	
+
+$(OUTDIR)/%.html: %.xml $(XMLDEPS) $(OUTDIR)
+	xsltproc xep.xsl "$<" > "$@"
+
+$(OUTDIR):
+	mkdir -p $(OUTDIR)
+
+.PHONY: clean
+clean:
+	rm -rf $(OUTDIR)