[Docs] Add a note about merging multiple documentation sources with Eldoc

Author: bbatsov

doc/modules/ROOT/pages/config/eldoc.adoc

@@ -73,3 +73,10 @@ If you're using CIDER alongside `clojure-lsp` you might prefer to use `clojure-l
 ----
 (remove-hook 'eldoc-documentation-functions #'cider-eldoc)
 ----
+
+TIP: If you're dealing with a lot of packages providing some ElDoc integration
+it's a good idea to learn about
+https://www.masteringemacs.org/article/seamlessly-merge-multiple-documentation-sources-eldoc[merging
+multiple documentation sources with ElDoc]. In brief - Emacs 28 added support
+for multiple documentation backends. Now you can read error messages from your
+linter or compiler *and* see code documentation at the same time. Cool stuff!