feat(aspen/emacs): Begin a complete emacs config revamp

I'm still on doom, but without all the cruft I've accumulated over the
last ~6 years it's actually good and fast and nice. Also, the config is
literate now!

The old emacs is still in .emacs.d, since occasionally I want to
reference it, but eventually I'll just get rid of it

Change-Id: Icda840d798594f7e6b188dba044494597d5f6043
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10999
Reviewed-by: aspen <root@gws.fyi>
Tested-by: BuildkiteCI

users/aspen/emacs/snippets/prolog-mode/tests

@@ -0,0 +1,11 @@
+# -*- mode: snippet -*-
+# name: tests
+# uuid: tests
+# key: tests
+# condition: t
+# --
+:- begin_tests(${1:name}).
+
+$0
+
+:- end_tests($1).

users/aspen/emacs/snippets/prolog-mode/use-module

@@ -0,0 +1,7 @@
+# -*- mode: snippet -*-
+# name: use-module
+# uuid: use-module
+# key: use
+# condition: t
+# --
+:- use_module(${1:library($2)}${3:, [$4]}).