Add convenience commands

- [ ] `:CreateSkeleton`

This would be called and create an entry in `~/.vim/exoskeleton/place` for the current directory of the file you're editing.

i.e. if you're in `/home/joe/code/stars/models/somefile.php`

It would create the `home-joe-code-stars-models` un der `~/.vim/exoskeleton`

- [ ] `:GetSkeletons`

Returns a list of all exoskeleton files (ft and place)

Start by locating the Vim command definitions and the existing handling for files under ~/.vim/exoskeleton. Check how the current file directory is represented, then implement the two requested commands and verify that CreateSkeleton creates the expected place entry and GetSkeletons lists the exoskeleton files.

Written by the indexing model from the issue text.