Add missing README entries and re-align columns

[fidgetingbits]

Description of changes

While working on #1535 I noticed there was a missing Dell entry, which got me looking for other missing entries. This adds all the other ones I found, as well as fixing up a couple typos in existing entries, and some table reformatting.

This was done by just manually going through results from for FILE in $(fd default.nix); do if \! rg $(dirname ${FILE}) README.md >/dev/null; then echo ${FILE} missing; fi; done | rg -v common and seeing which results were legitimately missing

I think I caught all of the real missing ones. While reviewing the raw table I decided to properly align most columns so that it's easier to edit/read.

Can do git diff -w to see the real non-alignment changes, which to summarize are:

Added:

• Kobol Helios 4
• Lenovo Legion Slim 5
• Malibal Aon S1
• Milk-V Pioneer
• Olimex TERES-I

Fixed:

• Framework 12th Gen Intel Core
• HP Probook 440G5

Things done

• Tested the changes in your own NixOS Configuration
• Tested the changes end-to-end by using your fork of nixos-hardware and
  importing it via <nixos-hardware> or Flake input