doc: don't included stray .md files in index.rst

If you change branches and have a generated .md file, index.rst
will pick it up.  Use the Makefile variable, not the contents of
the filesystem!

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

doc/Makefile

@@ -258,11 +258,11 @@ doc-clean:
 	$(RM) $(MANPAGES) $(MARKDOWN_WITH_SCHEMA) doc/.doc_version
 	$(RM) doc/deployable-lightning.{aux,bbl,blg,dvi,log,out,tex}
 
-doc/index.rst: $(MANPAGES:=.md)
+doc/index.rst: $(MANPAGES:=.md) Makefile
 	@$(call VERBOSE, "genidx $@", \
-	  find doc -maxdepth 1 -name '*\.[0-9]\.md' | \
-	  cut -b 5- | LC_ALL=C sort | \
-	  sed "s/\(.*\)\.\(.*\).*\.md/\1 <\1.\2.md>/" | \
+	  for m in $(MANPAGES); do basename $$m; done |  \
+	  LC_ALL=C sort | \
+	  sed "s/\(.*\)\.\(.*\)/\1 <\1.\2.md>/" | \
 	  $(PYTHON) devtools/blockreplace.py doc/index.rst manpages --language=rst --indent "   " \
 	)