Update cheatsheets

tldr/git-prune

@@ -11,11 +11,11 @@ source: https://github.com/tldr-pages/tldr.git
 
 - Report what would be removed by Git prune without removing it:
 
-`git prune --dry-run`
+`git prune {{[-n|--dry-run]}}`
 
 - Prune unreachable objects and display what has been pruned to `stdout`:
 
-`git prune --verbose`
+`git prune {{[-v|--verbose]}}`
 
 - Prune unreachable objects while showing progress: