This will add an additional alias `l.` to only show dotfiles and
directories.
Additionally the `--classify` flag [1] is added to all ls/exa commands which
will append a specific character to the listed files according to the
filetype.
[1] https://the.exa.website/features/colours#classify
This changes the output to be human-readable.
Additionally du will now only check 2 levels deep (can be overridden by
explicitly setting `-d <depth>`).
