Rename run to line and add some explanatory comments ✏

The name run was a relict of the time where a line consisted of a set of runs with same alignment. While these runs still exist conceptually, they are all stored flatly together in what was now renamed from `run`  to `line`.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/layout/background.rs b/src/layout/background.rs
index 6b605d7f..b331ba3c 100644
--- a/src/layout/background.rs
+++ b/src/layout/background.rs
@@ -16,9 +16,9 @@ impl Layout for NodeBackground {
         for frame in layouted.frames_mut() {
             let element = Element::Geometry(Geometry {
                 shape: Shape::Rect(frame.size),
-                fill: self.fill.clone(),
+                fill: self.fill,
             });
-            frame.elements.insert(0, (Point::ZERO, element))
+            frame.elements.insert(0, (Point::ZERO, element));
         }
 
         layouted