mod(container): make reposition public and split from resize

examples/styles/palette.zig

@@ -94,7 +94,8 @@ pub fn main() !void {
         }
 
         try renderer.resize();
-        container.resize(.{}, renderer.size);
+        container.resize(renderer.size);
+        container.reposition(.{});
         try renderer.render(@TypeOf(container), &container);
         try renderer.flush();
     }

examples/styles/text.zig

@@ -149,7 +149,8 @@ pub fn main() !void {
         }
 
         try renderer.resize();
-        container.resize(.{}, renderer.size);
+        container.resize(renderer.size);
+        container.reposition(.{});
         try renderer.render(@TypeOf(container), &container);
         try renderer.flush();
     }