Remove duplicated command

Author: lukabot

README.md

@@ -563,12 +563,6 @@ git clean -f
 git clean -f -d
 ```
 
-
-__Alternatives:__
-```sh
-git clean -df
-```
-
 ## Update all the submodules
 ```sh
 git submodule foreach git pull

tips.json

@@ -183,8 +183,7 @@
     "tip": "git clean -f"
 }, {
     "title": "Forcefully remove untracked directory",
-    "tip": "git clean -f -d",
-    "alternatives": ["git clean -df"]
+    "tip": "git clean -f -d"
 }, {
     "title": "Update all the submodules",
     "tip": "git submodule foreach git pull",