create-sym-link

Create a symbolic `link` to `target` via [Files/createSymbolicLink](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/nio/file/Files.html#createSymbolicLink(java.nio.file.Path,java.nio.file.Path,java.nio.file.attribute.FileAttribute...)). As of this writing, JDKs do not recognize empty-string `target` `""` as the cwd. Consider instead using a `target` of `"."` to link to the cwd.