doc: decode the objects.inv file

Sphinx creates an objects.inv file that contains a mapping of IDs and
locations in the docs. The UI needs this mapping to be able to resolve
links within the descriptions of config options.

The UI would require additional dependencies to decode the objects.inv
file, so providing the decoded version with the documentation is
easier.

Signed-off-by: Ruth Fuchss <ruth.fuchss@canonical.com>

Makefile

@@ -138,13 +138,17 @@ doc-setup: client
 	rm -Rf doc/.sphinx/.doctrees
 
 .PHONY: doc
-doc: doc-setup doc-incremental
+doc: doc-setup doc-incremental doc-objects
 
 .PHONY: doc-incremental
 doc-incremental:
 	@echo "Build the documentation"
 	. $(SPHINXENV) ; LOCAL_SPHINX_BUILD=True sphinx-build -c doc/ -b dirhtml doc/ doc/html/ -d doc/.sphinx/.doctrees -w doc/.sphinx/warnings.txt
 
+.PHONY: doc-objects
+doc-objects:
+	. $(SPHINXENV); cd doc/html; python3 -m sphinx.ext.intersphinx 'objects.inv' > objects.inv.txt
+
 .PHONY: doc-serve
 doc-serve:
 	cd doc/html; python3 -m http.server 8001