Add make recipe to bump release version in HTML files

Makefile

@@ -95,6 +95,8 @@ release:
 	$(SED) -i -e "/version =/s/=.*/= '$(VERSION)'/" -e "/release =/s/=.*/= '$(VERSION)'/" docs/source/conf.py
 	$(SED) -i "s/[Uu]nreleased/`date +%Y-%m-%d`/" CHANGES.md
 	$(SED) -ri 's,cdn.conversejs.org/$(VERSION_FORMAT),cdn.conversejs.org/$(VERSION),' docs/source/quickstart.rst
+	$(SED) -ri 's,cdn.conversejs.org/$(VERSION_FORMAT),cdn.conversejs.org/$(VERSION),' *.html
+	$(SED) -ri 's,cdn.conversejs.org/$(VERSION_FORMAT),cdn.conversejs.org/$(VERSION),' demo/*.html
 	make pot
 	make po
 	make po2json