doc: Replace screenshot

The new screenshot demonstrates `--align-left`

Author: KSXGitHub

README.md

@@ -41,7 +41,7 @@ The benchmark was generated by [a GitHub Workflow](https://github.com/KSXGitHub/
 
 ## Demo
 
-![screenshot](https://user-images.githubusercontent.com/11488886/120894518-04c41580-c643-11eb-9089-71822b543a2c.png)
+![screenshot](https://user-images.githubusercontent.com/11488886/127254941-d1fb30d8-18e0-40ac-a212-bbd6463aa624.png)
 
 [![asciicast of pdu command](https://asciinema.org/a/416663.svg)](https://asciinema.org/a/416663)