Refactor: add missing or_directory where needed.

This commit adds the missing `_or_directory` to any example which is
specifying an action affecting a file or a directory, but uses the
token `{{path/to/file}}` instead of `{{path/to/file_or_directory}}`.

pages/common/chmod.md

@@ -8,7 +8,7 @@
 
 - Give the user rights to [r]ead and [w]rite to a file/directory:
 
-`chmod u+rw {{file}}`
+`chmod u+rw {{file_or_directory}}`
 
 - Remove executable rights from the [g]roup: