Readme: document cd_parent

README.md

@@ -99,6 +99,7 @@ Changes will available only in a new shell session.
 The Fuck tries to match rule for the previous command, create new command
 using matched rule and run it. Rules enabled by default:
 
+* `cd_parent` – changes `cd..` to `cd ..`;
 * `git_no_command` – fixes wrong git commands like `git brnch`;
 * `git_push` – adds `--set-upstream origin $branch` to previous failed `git push`;
 * `no_command` – fixes wrong console commands, for example `vom/vim`;