[1.5.x] Fixed #19266 -- Added Texinfo documentation target

Thanks orontee for the report and initial patch.
Backport of a79d920a56 from master.

docs/conf.py

@@ -233,6 +233,16 @@ man_pages = [
 ]
 
 
+# -- Options for Texinfo output ------------------------------------------------
+
+# List of tuples (startdocname, targetname, title, author, dir_entry,
+# description, category, toctree_only)
+texinfo_documents=[(
+    master_doc, "django", "", "", "Django",
+    "Documentation of the Django framework", "Web development", False
+)]
+
+
 # -- Options for Epub output ---------------------------------------------------
 
 # Bibliographic Dublin Core info.