Merge pull request #478 from abloch/master

add import to columns example in README.md

README.cn.md

@@ -205,6 +205,7 @@ Rich 可以将内容通过排列整齐的，具有相等或最佳的宽度的[
 
 ```python
 import os
+import sys
 
 from rich import print
 from rich.columns import Columns

README.es.md

@@ -219,6 +219,7 @@ Rich puede representar contenido en [columnas](https://rich.readthedocs.io/en/la
 
 ```python
 import os
+import sys
 
 from rich import print
 from rich.columns import Columns

README.md

@@ -258,6 +258,7 @@ Rich can render content in neat [columns](https://rich.readthedocs.io/en/latest/
 
 ```python
 import os
+import sys
 
 from rich import print
 from rich.columns import Columns