Migrate .gitconfig to home-manager

legacy/.gitconfig

@@ -1,45 +0,0 @@
-[color]
-	ui = auto
-[alias]
-	co = checkout
-	st = status
-	di = diff -w --no-prefix
-	df = diff
-	dc = diff --cached
-	ci = commit
-	br = branch
-	lg = log -p --decorate=full --show-signature
-	lol = log --graph --decorate=full --pretty=oneline --abbrev-commit
-	lola = log --graph --decorate=full --pretty=oneline --abbrev-commit --all
-	ls = ls-files
-	# Show files ignored by git:
-	ign = ls-files -o -i --exclude-standard
-[apply]
-	whitespace = nowarn
-[push]
-	default = tracking
-[rebase]
-	stat = yes
-[format]
-	pretty = fuller
-[fetch]
-	prune = yes
-[credential "https://source.developers.google.com"]
-	helper = gcloud.sh
-[core]
-	autocrlf = input
-[branch]
-	# 0 times I wanted this when doing "git checkout".
-	autoSetupMerge = false
-	# Set up new branches in a way that "git pull" does a rebase by default.
-	autoSetupRebase = always
-
-# Commit signing, currently using ssh@mars -- to be switched to sign@mars after 2026-05-15
-[gpg]
-	format = ssh
-[commit]
-	gpgsign = true
-[user]
-	signingkey = key::ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBNwSX/Ib6kNzgRKqWfcb3HsAQQo++Gt9KeXSvP6NDk6YQPjDsi+//IiBovgLjQ34El+x8l8y3aYhfIGlCyX7aOM= sign@mars
-	name = Artem Sheremet
-	email = dot.doom@gmail.com