Add a ziphtml target for preparing the documentation to be uploaded to pypi

doc/Makefile

@@ -41,6 +41,10 @@ html:
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 
+ziphtml: html
+	rm -f $(BUILDDIR)/html/wsme-documentation.zip
+	cd $(BUILDDIR)/html && zip -r wsme-documentation.zip .
+
 dirhtml:
 	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
 	@echo