Use XDG-compatible plugin path when available
Use XDG-compatible plugin path when available

If the `tmux.conf` file is found at a XDG_CONFIG_HOME, use this
directory to store the plugins instead of `$HONE/.tmux/`.

This is only effective if the user has not overridden the value of
`TMUX_PLUGIN_MANAGER_PATH` in their configuration file.

bruno-/tpm,tmux-plugins/tpm