fix topics html pages

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@53526 15284696-431f-4ddb-bdfa-cd5b030d7da7

man/Makefile

@@ -25,7 +25,7 @@ categories = \
 
 IDXCATS := $(foreach cat,$(categories),$(lastword $(subst :, ,$(cat))))
 
-IDXSRC = full_index index $(IDXCATS)
+IDXSRC = full_index index topics $(IDXCATS)
 
 INDICES := $(patsubst %,$(HTMLDIR)/%.html,$(IDXSRC))