Update README.md

Corrected small error in the readme from my previous key binding modification.

README.md

@@ -208,7 +208,7 @@ I'd install it first and add its setup line :
 
 - **Managing tabs with bufferline!**
 
-- <kbd> Shift </kbd> <kbd> TAB or Shift TAB </kbd> cycle through opened tabs
+- <kbd> TAB </kbd> or <kbd> Shift TAB </kbd> cycle through opened tabs
 - <kbd> Shift </kbd> <kbd> x </kbd> close current tab
 - <kbd> Shift </kbd> <kbd> t </kbd> open new tab