Refactor/vim.pack

[oriori1703]

Migrate from lazy.nvim to vim.pack.

Caution

This is still a WIP experiment, and we may decide to stick with lazy.nvim
There is still more work to do and I'm looking for feedback.

Tasks / need feedback:

• Choose between one big vim.pack.add in the beginning vs vim.pack.add near each relevant require
• Better doc strings for vim.pack
• Measure the startuptime diff
• Maybe add more lazy loading for heavier plugins? Seems like the performance is good enough without it :)
  • If so, should it be using plain autocmds or using mini's MiniMisc.safely()

If you want to make it easier to see the diff, I suggest cloning and running git diff --ignore-all-space --ignore-blank-lines e099979958b110ab20524e67e1f57ddef9eb6cb0 (or the commit id of the first commit, if I rebase this branch)

fixes #1630

[nathanzeng]

Great work, I am strongly in favor of using vim.pack

Startup Time Diff
This will differ based on hardware, but I was getting 65-75ms with this branch and 42-47ms with the master branch.
I measured using nvim --startuptime startup.log and looking at the bottom of the log file.

Lazy Loading
I don't think it's necessary, but maybe add a note saying to look into autocommands, MiniMisc, lazy.nvim, etc. if concerned.

[oriori1703]

I also did some testing of my own and the results are promising :)

It seems that after adding vim.loader.enable the vim.pack is only 3-4 ms slower than lazy (both of them were measured after a couple of restarts to allow them to compile the bytecode).

lazy.nvim (master 9b4fbc5)	vim.pack (18c335c)	vim.pack + vim.loader (bcf7a2c)
064.016	094.045	067.264

Relevant system info:

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> inxi
CPU: 8-core AMD Ryzen 7 5800X (-MT MCP-) speed/min/max: 4195/614/5363 MHz
Kernel: 7.0.0-200.nobara.fc43.x86_64 x86_64 Up: 2d 13h 8m
Mem: 9.5/31.25 GiB (30.4%) Storage: 5.48 TiB (12.0% used) Procs: 511
Shell: fish inxi: 3.3.40

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> nvim --version
NVIM v0.12.1
Build type: Release
LuaJIT 2.1.1774638290

orip@Ori-pc ~/.c/upstream-kickstart (refactor/vim.pack)> ghostty --version
Ghostty 1.3.1

Version
  - version: 1.3.1
  - channel: stable
Build Config
  - Zig version   : 0.15.2
  - build mode    : .ReleaseFast
  - app runtime   : .gtk
  - font engine   : .fontconfig_freetype
  - renderer      : renderer.generic.Renderer(renderer.OpenGL)
  - libxev        : io_uring
  - kernel version: 7.0.0-200.nobara.fc43.x86_64
  - desktop env   : other
  - GTK version   :
    build         : 4.20.3
    runtime       : 4.20.4
  - libadwaita    : enabled
    build         : 1.8.4
    runtime       : 1.8.5
  - libX11        : enabled
  - libwayland    : enabled

[feketegy]

I just converted my own configs to use vim.pack exclusively without any issues; and the startup time is not noticeable at all between vim.pack and lazy.nvim.

Given that the current config uses lazy require at each relevant point in the file, I would favor replicating that with vim.pack. I think it would be clearer for users that all related code are grouped together.