Makefile: add a clean target

Author: eworm-de

Makefile

@@ -23,3 +23,6 @@ all: $(CAPSMAN) $(LOCAL) $(HTML)
 	sed -e '/\/interface\/wireless/d' -e 's/%PATH%/caps-man/' -e 's/%TEMPL%/$(suffix $@)/' \
 		-e '/^# !!/,/^# !!/c # !! Do not edit this file, it is generated from template!' \
 		< $< > $@
+
+clean:
+	rm -f $(HTML)