docs: pcloud: update root_folder_id instructions

docs/content/pcloud.md

@@ -152,14 +152,23 @@ However you can set this to restrict rclone to a specific folder
 hierarchy.
 
 In order to do this you will have to find the `Folder ID` of the
-directory you wish rclone to display.  This will be the `folder` field
-of the URL when you open the relevant folder in the pCloud web
-interface.
+directory you wish rclone to display. This can be accomplished by executing
+the ```rclone lsf``` command using a basic configuration setup that does not
+include the ```root_folder_id``` parameter.
 
-So if the folder you want rclone to use has a URL which looks like
-`https://my.pcloud.com/#page=filemanager&folder=5xxxxxxxx8&tpl=foldergrid`
-in the browser, then you use `5xxxxxxxx8` as
-the `root_folder_id` in the config.
+The command will enumerate available directories, allowing you to locate the
+appropriate Folder ID for subsequent use.
+
+Example:
+```
+$ rclone lsf --dirs-only -Fip --csv TestPcloud:
+dxxxxxxxx2,My Music/
+dxxxxxxxx3,My Pictures/
+dxxxxxxxx4,My Videos/
+```
+
+So if the folder you want rclone to use your is "My Music/", then use the returned id from ```rclone lsf``` command (ex. `dxxxxxxxx2`) as
+the `root_folder_id` variable value in the config file.
 
 {{< rem autogenerated options start" - DO NOT EDIT - instead edit fs.RegInfo in backend/pcloud/pcloud.go then run make backenddocs" >}}
 ### Standard options