Remove "extras", using Makefile to same purpose

Makefile

@@ -1,4 +1,4 @@
-.PHONY: test build mu davmail all
+.PHONY: test build mu all
 
 test:
 	sudo nixos-rebuild test --flake .
@@ -15,12 +15,10 @@ mu:
 		--my-address=evie.litherland-smith@ukaea.uk \
 		--my-address=elitherl@jet.uk
 
-extra/davmail.properties:
+.davmail.properties:
 	touch $@
 
-~/.davmail.properties: extra/davmail.properties
+~/.davmail.properties: .davmail.properties
 	cp $? $@
 
-davmail: ~/.davmail.properties
-
-all: test mu davmail
+all: mu ~/.davmail.properties

extra/mu_init.sh

@@ -1,3 +0,0 @@
-#!/usr/bin/env sh
-
-mu init --maildir ~/.mail --my-address=e.litherlandsmith@proton.me --my-address=evie@xenia.me.uk --my-address=evie@litherlandsmith.slmail.me --my-address=e.litherlandsmith@icloud.com --my-address=evie.litherland-smith@ukaea.uk --my-address=elitherl@jet.uk