Add notes about copying frames and cels on continues layers

Author: thkwznk

copy-cels.md

@@ -12,6 +12,8 @@ Use the [timeline](timeline.md) to copy cels:
 Note that you can copy cels beyond the end of the animation. In this
 case new empty frames are created automatically.
 
+When copying cels on a [continuous layer](continuous-layers.md), copied cels will be [linked](linked-cels.md) to the original ones.
+
 ---
 
 **SEE ALSO**

copy-frames.md

@@ -9,6 +9,10 @@ Use the [timeline](timeline.md) to copy frames:
 3. Hold <kbd>Ctrl</kbd> or <kbd>Alt</kbd> key and start dragging.
 4. Drop the copy where you want, holding <kbd>Ctrl</kbd> or <kbd>Alt</kbd> keys.
 
+Note that you can copy frames beyond the end of the animation, extending it.
+
+When copying frames on a [continuous layer](continuous-layers.md), copied cels will be [linked](linked-cels.md) to the original ones.
+
 ---
 
 **SEE ALSO**