Update commentary.

Author: jcs090218

ivy-file-preview.el

@@ -27,7 +27,17 @@
 
 ;;; Commentary:
 ;;
-;; Preview the current ivy file selection.
+;; This global minor mode enhanced the user experience while controlling
+;; through `ivy' interface during some previewable commands.
+;;
+;; You can enable this minor mode by doing the following execution,
+;;
+;;   `(ivy-file-preview-mode 1)`
+;;
+;; Some previewable commands can be a file, path, or search restult.
+;; The file and path can be either absolute/relative file path.  The
+;; search result accepts cons cell for either (line . column) or a
+;; integer (position).
 ;;
 
 ;;; Code: