[displaymanager] add more python doc strings

src/modules/displaymanager/main.py

@@ -45,6 +45,7 @@ desktop_environments = [
 
 def find_desktop_environment(root_mount_point):
     """
+    Checks which desktop environment is currently installed.
 
     :param root_mount_point:
     :return:
@@ -60,6 +61,7 @@ def find_desktop_environment(root_mount_point):
 
 def have_dm(dm_name, root_mount_point):
     """
+    Checks if display manager is properly installed.
 
     :param dm_name:
     :param root_mount_point: