doc + adjust values

Author: anpawo

videocode/shader/ishader.py

@@ -29,6 +29,9 @@ def at(self, *, start: sec, duration: sec = SINGLE_FRAME, offset: maybe[frame] =
         return self
 
     def resolve(self, start: sec, duration: sec, offset: maybe[frame]) -> tuple[sec, sec, maybe[frame]]:
+        """
+        Use self default values if any else given ones.
+        """
         return (
             Maybe(self.start) | start,
             Maybe(self.duration) | duration,

videocode/template/input/Shadow.py

@@ -16,7 +16,7 @@ class Shadow(Polygon):
     def __init__(
         self,
         shape: Polygon,
-        offset: tuple[wnumber, wnumber] = (-0.15, -0.15),
+        offset: tuple[wnumber, wnumber] = (0.3, -0.3),
         color: rgba = BLACK | 0.5,
     ):
         super().__init__(