git: move personal config to separate file

Stuff like credential stores (which are different by platform) tend to clutter the main file, so I'm shoving them in their own file which won't be touched by automated setup tools

git/.config/git/personal.gitconfig

@@ -0,0 +1,23 @@
+# User identity
+[user]
+	name = Erin
+	email = github@eritbh.me
+
+# Command aliases
+[alias]
+	l = log --oneline --decorate --graph
+	la = log --oneline --decorate --graph --all
+	wmerge = merge --no-commit -Xignore-space-change
+	lc = diff --numstat
+	pushup = push --set-upstream origin @
+	s = stash save --include-untracked
+	sp = stash pop
+	sl = stash list
+
+# Rebase local commits on top of remote commits when running `git pull`
+[pull]
+	rebase = true
+
+# New repos have a default branch name of "main"
+[init]
+	defaultBranch = main

git/.gitconfig

@@ -1,16 +1,2 @@
-[user]
-	name = Erin
-	email = github@eritbh.me
-[alias]
-	l = log --oneline --decorate --graph
-	la = log --oneline --decorate --graph --all
-	wmerge = merge --no-commit -Xignore-space-change
-	lc = diff --numstat
-	pushup = push --set-upstream origin @
-	s = stash save --include-untracked
-	sp = stash pop
-	sl = stash list
-[pull]
-	rebase = true
-[init]
-	defaultBranch = main
+[include]
+	path = ~/.config/git/personal.gitconfig