Review change to the wiki

[tomm1996]

Hello, I just edited the description of the unlink method in the Wiki as proposed in wkh237#132 and expected a pull request dialogue or something similar, but apparently it just got got edited instead. I just wanted to notify you about it.

- Delete a file at path. Note that there will be no error if the file to be deleted does not exist.
+ Delete a file or an entire folder at path. Note that there will be no error if the file to be deleted does not exist.