Update call hierarchy documentation (#4324)

Author: FelipeCortez

docs/tutorials/clojure-guide.md

@@ -191,13 +191,10 @@ uses it to show the reference count of a function/variable. They are enabled by
 
 ### Call hierarchy
 
-This feature returns the call hierarchy of a function/method.
-As of now, `clojure-lsp` only supports returning the incoming-call hierarchy.
+With [lsp-treemacs](https://github.com/emacs-lsp/lsp-treemacs), installed, `lsp-treemacs-call-hierarchy` returns the incoming call hierarchy of a function/method by default and the outgoing hierarchy with the `C-u` prefix argument.
 
 ![incoming-call hierarchy](images/clojure-call-hierarchy.png "incoming-call hierarchy")
 
-It uses [lsp-treemacs](https://github.com/emacs-lsp/lsp-treemacs), which you should install to use this feature.
-
 ### Formatting
 
 For LSP formatting, `clojure-lsp` use [cljfmt](https://github.com/weavejester/cljfmt) with support for all known `cljfmt`