man rm

By default, rm does not remove directories. Use the --recursive (-r or -R) option to remove each listed
directory, too, along with all of its contents.

   To remove a file whose name starts with a '-', for example '-foo', use one of these commands:

          rm -- -foo

          rm ./-foo

   Note that if you use rm to remove a file, it might be possible to recover some of its contents, given suffi?
   cient expertise and/or time.  For greater assurance that the  contents  are  truly  unrecoverable,  consider
   using shred.