revert: line breaks in background-option.md (#55)

Author: Craun718

.changes/background-option.md

@@ -6,7 +6,6 @@ Optimize `background` option of `BubbleList` component.
 
 BREAKING CHANGES:
 
-- Use `left-solid`, `right-solid`, `transparent` and `solid` as the value of
-`background` option.
+- Use `left-solid`, `right-solid`, `transparent` and `solid` as the value of `background` option.
 - Default to use `right-solid` as the value of `background` option in `Bubble` component.
 - Remove `left-only` and `right-only` value in `Bubble` component.