Format

README.md

@@ -328,6 +328,9 @@ Format
 {123456:10,}     # '   123,456'
 {123456:10_}     # '   123_456'
 {123456:+10}     # '   +123456'
+{-123456:=10}    # '-   123456'
+{123456: }       # ' 123456'
+{-123456: }      # '-123456'
 ```
 
 ```python