[ELPA] package proposal: fannypack.el

[Theodor Thornhill <theo@thornhill.no>]

Hi there!

I've been using a small utility for some time that might be useful for
others.  It's called fannypack.el, and is a file management/file
navigation helper.  So, what does it do?

When working on some feature, I usually checkout a branch, then start
working.  After a while, some files reveal themselves as more relevant
to the ongoing work than others, and I want to be able to jump to them
quickly, without them getting lost in the sea of buffers.  In addition,
I want it to be persisted, so that when I restart my emacs session, I
still can jump to things quickly.  This demotes the general
switch-to-buffer mechanism to store the bulk of buffers, and the
fannypack provides some clarity.  When changing branches, or projects,
the fannypacks are automatically updated to the relevant ones.  So to
sum it up:

* Keep different subsets of project files easily accessible, delimited
  by branch

* Automatically update what sets of files are shown

* Persist the data between sessions


The keybinds I use at the moment for this are:
```
(global-set-key (kbd "s-f") 'fannypack-pick)
(global-set-key (kbd "s-k") 'fannypack-drop)
(global-set-key (kbd "s-m") 'fannypack-place)
(global-set-key (kbd "s-+") 'fannypack-promote)
(global-set-key (kbd "s--") 'fannypack-demote)
(global-set-key (kbd "s-n") 'fannypack-feeling-lucky)
(global-set-key (kbd "s-d") 'fannypack-default-directory)
```

I'm not sure if this is wanted in ELPA or anywhere else, but I find it
very useful, and others might too.

Source can be found at https://git.sr.ht/~theo/fannypack

All the best,
Theodor Thornhil