docs: colorpicker text optimize (ant-design#48008)

Author: Roxannej

components/color-picker/demo/size.md

@@ -1,7 +1,7 @@
 ## zh-CN
 
-触发器有大、中、小三种尺寸，若不设置 size，则尺寸为中。
+触发器有大、中、小三种尺寸，若不设置 size，则尺寸默认为中。
 
 ## en-US
 
-The trigger has three sizes: large, medium and small. If size is not set, the size will be medium.
+The trigger has three sizes: large, medium and small. If size is not set, the size will be medium by default.