Adding "livehtml" build target

Author: Alexander Obuhovich

Makefile

@@ -42,6 +42,9 @@ html:
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 
+livehtml:
+	sphinx-autobuild -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+
 dirhtml:
 	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
 	@echo