Fix include for liq files.

website/Makefile

@@ -3,7 +3,6 @@
 PWD := $(shell pwd)
 GENERATED_DOC_DIR := $(PWD)/../liquidsoap/_build/default/doc
 GENERATED_INTERPRETER_DIR := $(PWD)/../liquidsoap/_build/default/src/js
-PANDOC := pandoc --syntax-definition=liquidsoap.xml --highlight=pygments --lua-filter=tools/option-anchors.lua --filter=pandoc-include
 NODE := $(shell which node)
 
 # Versions for which documentation should be built and included
@@ -103,7 +102,7 @@ define VERSIONED_RULES
 $(PWD)/html/doc-$(version)/%.html: $(PWD)/content/doc-$(version)/%.md $(PWD)/template-$(version).html
 	@echo Converting $$(<) to $$(@)...
 	@test -d $$(shell dirname $$(@)) || (mkdir -p $$(shell dirname $$(@)))
-	@$(PANDOC) --template template-$(version).html --metadata version=$(version) --metadata versions="$(VERSIONS)" --metadata pagetitle="$$(basename $$(notdir $$@))" -i $$< -o $$@
+	@pandoc $$< -t json | pandoc-include --directory $(PWD)/content/doc-$(version)/liq | pandoc -f json --syntax-definition=liquidsoap.xml --highlight=pygments --lua-filter=tools/option-anchors.lua --template template-$(version).html --metadata version=$(version) --metadata versions="$(VERSIONS)" --metadata pagetitle="$$(basename $$(notdir $$@))" -o $$@
 
 $(PWD)/html/doc-$(version)/images/%: $(PWD)/content/doc-$(version)/images/%
 	@echo "$$(<) -> $$(@)"