[NaCl Docs] Add a new doc build configuration: devsite-staging.

native_client_sdk/src/doc/Makefile

Index: native_client_sdk/src/doc/Makefile
diff --git a/native_client_sdk/src/doc/Makefile b/native_client_sdk/src/doc/Makefile
index 2fc4e0fe2798c3a6af278caa846d8f88b63d05ec..d9faadf1d469fd9f66a8e00623b27def4ce195fd 100644
--- a/native_client_sdk/src/doc/Makefile
+++ b/native_client_sdk/src/doc/Makefile
@@ -183,9 +183,18 @@ pseudoxml:
 
 devsite-prod:
 	$(SPHINXBUILD) -b devsite -D devsite_production_mode=1 $(ALLSPHINXOPTS) $(BUILDDIR)/devsite-prod
+	rm -rf $(BUILDDIR)/devsite-staging/images
+	cp -r $(BUILDDIR)/devsite-prod/_images $(BUILDDIR)/devsite-prod/images
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/devsite-prod."
 
+devsite-staging:
+	$(SPHINXBUILD) -b devsite -D devsite_foldername=$(USER) -D devsite_production_mode=1 $(ALLSPHINXOPTS) $(BUILDDIR)/devsite-staging
+	rm -rf $(BUILDDIR)/devsite-staging/images
+	cp -r $(BUILDDIR)/devsite-staging/_images $(BUILDDIR)/devsite-staging/images
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/devsite-staging."
+
 devsite:
 	$(SPHINXBUILD) -b devsite -D devsite_production_mode=0 $(ALLSPHINXOPTS) $(BUILDDIR)/devsite
 	@echo