Docs: Add a test target for the documentation

The test target will run, but won't fail the build if there are issues.
This is so it can be added to the jenkins build and run until it passes.
At that point, it can be made to fail if there's an error.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I5810643ee143f9db4f1cd388531161d4398d596c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75497
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 12f0ec7..17aec29 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -55,12 +55,18 @@
 livesphinx:
 	$(MAKE) -f Makefile.sphinx livehtml SPHINXOPTS="$(SPHINXOPTS)"
 
+test:
+	@echo "Test for logging purposes - Failing tests will not fail the build"
+	-$(MAKE) -f Makefile.sphinx clean && $(MAKE) -K -f Makefile.sphinx html
+	-$(MAKE) -f Makefile.sphinx clean && $(MAKE) -K -f Makefile.sphinx doctest
+
 help:
 	@echo "all            - Builds coreboot porting guide PDF (outdated)"
 	@echo "sphinx         - Builds html documentation in _build directory"
 	@echo "clean          - Cleans intermediate files"
 	@echo "clean-sphinx   - Removes sphinx output files"
 	@echo "distclean      - Removes PDF files as well"
+	@echo "test           - Runs documentation tests"
 	@echo
 	@echo "  Makefile.sphinx builds - run with $(MAKE) -f Makefile-sphinx [target]"
 	@echo