encodeFS is not documented

I noticed that encodeFS lacks haddock documentation about what it does, eg see here:
https://hackage.haskell.org/package/filepath-1.5.4.0/docs/System-OsPath.html#v:encodeFS

By process of elimination on the 3 strategies that the documentation discusses, I was able to guess that it mimics the behavior of the base library.

I think this should be documented, like decodeFS is.

Start by locating encodeFS in the System.OsPath module and compare its existing documentation with decodeFS. Review the three documented encoding strategies and the linked Hackage entry to confirm that encodeFS follows the base library behavior. Done means the Haddock documentation explains what encodeFS does and matches the style of decodeFS.

Written by the indexing model from the issue text.