add radius to container flutter code example

Example 1: flutter container rounded corners

Container(
  decoration: BoxDecoration(
    border: Border.all(
      color: Colors.red[500],
    ),
    borderRadius: BorderRadius.all(Radius.circular(20))
  ),
  child: ...
)

Example 2: flutter container radius

Container(
  child: Text("It's text..."),
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10),  // radius of 10
    color: Colors.green  // green as background color
  )
)

Example 3: flutter container border radius

Container(
  child: Text(
    'This is a Container',
    textScaleFactor: 2,
    style: TextStyle(color: Colors.black),
  ),
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10),
    color: Colors.white,
    boxShadow: [
      BoxShadow(color: Colors.green, spreadRadius: 3),
    ],
  ),
  height: 50,
),