[gtksourceview] languagemanager: add note about resource URIs

[Christian Hergert <chergert src gnome org>]

commit 777cbbc12926bee7c5a2ffc236d8fd2c85b777e9
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 28 14:24:24 2022 -0800

    languagemanager: add note about resource URIs

 gtksourceview/gtksourcelanguagemanager.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gtksourceview/gtksourcelanguagemanager.c b/gtksourceview/gtksourcelanguagemanager.c
index 5cf7f7b8..89921f77 100644
--- a/gtksourceview/gtksourcelanguagemanager.c
+++ b/gtksourceview/gtksourcelanguagemanager.c
@@ -242,6 +242,10 @@ notify_search_path (GtkSourceLanguageManager *mgr)
  * language files are loaded for the first time. In practice
  * to set a custom search path for a `GtkSourceLanguageManager`,
  * you have to call this function right after creating it.
+ *
+ * Since GtkSourceView 5.4 this function will allow you to provide
+ * paths in the form of "resource:///" URIs to embedded `GResource`s.
+ * They must contain the path of a directory within the `GResource`.
  */
 void
 gtk_source_language_manager_set_search_path (GtkSourceLanguageManager *lm,