Add utils section, update `git s`, adjust INSTALL

  * Add the utils section to install scripts I keep copying between
    machines. Really should've set this one up sooner, but kind of just
    didn't and don't really know why.

  * Update the `git s` alias to use `git status -uno` instead of `git
    show` to match my current work configuration (i.e., where
    I primarily use git nowadays, so its config and setup tends to be
    ahead of dotfiles a lot of the time).

  * Adjust the `INSTALL` variable under Makefiles to remove the `-b` by
    default (this is only used if running with `bmake -r`, which
    I never documented, so probably wouldn't have been noticed in most
    cases). Add an `INSTALL_FILE` variable that contains an additional
    `-T` argument under Linux to ensure that src/dest are both treated
    as files instead of file/dir respectively.
Add Brewfile for macOS package use

Really should've added this sooner, but had not gotten around to it.
Not all packages in it are supported on ARM Macs, so not every
environment is the same, but at least the omissions are things that
aren't requirements.
Update vim-go to v1.25
Remove ultisnips
Add kitty config
Align split keys with tmux

Align my hlwm split keys with tmux's.
Set optional VERSION_CONTROL variable

Default the optional VERSION_CONTROL to numbered for use with install.
This will create backups of files on install so that there's a rollback
you can do without too much effort.
Fix git-eh

Older version of git-eh got committed for some reason, so fixing that
because I use eh and links of it to tweak config.
Update polybar/config
Add source URLs into gitmodules

Add source URLs into gitmodules so they can be traced back to their
sources and updated if needed. Should've done that previously, but
didn't think about it.

Add .gitmodules to .gitignore to require any untracked changes to be
forcefully added to the index. There's an included update-modules to
temporarily set all submodule URLs to their origins, sync, run
a command, and then revert back to '.' as the URL.
Add polybar config, update herbstluft

Add polybar config to dotfiles and update the herbstluftwm config to
include it. This also adds a few checks for things before running them,
like xmodmap and co.
Update ep to specify min / max search depth

Update the EP_PATHS variable to include the minimum and maximum search
depth of paths. Eventually I'd like to replace this with something like
locate/plocate, but for now, this works. Maybe throw a cache in there
if it ends up being necessary, but so far, this works alright if you
don't get too wild with how many git repos you keep around.
Support normal jq escape codes

git-todo is written for gojq, so the \xHH escape broke when running it
on a system with only normal jq. This updates the escape to use \uHHHH
instead, so the difference is only in how the code is expressed.
Add -b to default install parameters

Add a -b (backup) parameter to default install parameters. This would
include more arguments if I had the time, but this is the minimum set
that're compatible between GNU install and FreeBSD's install.
Fix missing dependency for ~/bin/git- targets

Add a dependency on bin_${gt} for ~/bin/git- targets, since that was
missing and made it hard to keep things up to date.
Convert subtrees to submodules

Convert subtrees under vim/ to submodules, and update all submodules to
be stored in the repository via git-subtrac. This is a little less
tedious to manage than git-subtree (also by the author of git-subtrac),
and makes it much easier to upstream any local changes if I want to

To make it a little easier, the install targets under the makefile now
depend on the submodules target. This does mean the makefiles can't be
used on their own, but it's fine for now, that was the assumption for
most of this repo's lifespan.
Remove yats.vim

Unused and has a submodule reference that I'm not going to fix.
Fix zsh plugin dir creation

  * Fix history plugin having the wrong install target.
  * Add plugin directory as a dependency to all plugins' files.
Replace <subdir>/ paths with absolute path var

Replace lal the <subdir>/ paths in subdir Makefiles with an absolute
path var for the parse dir. This should be a little more reliable than
what's currently being done, and makes it easier to run the makefiles
from their directories if needed.