mail: Temporarily switch to Thunderbird

After much struggle with all clients known to me, I now use Thunderbird.
I might not keep using it for a longer time, so I kept the old
configuration and disabled it, so it can be reused at a later time.

Because Thunderbird doesn’t support nice declarative configuration, I
don’t see much sense in configuring the accounts declaratively, when the
settings for the accounts (which is much more) have to be configured
manually.

users/simon/modules/git.nix

@@ -75,7 +75,7 @@
       (condition: {
         inherit condition;
         contents = {
-          user.email = config.accounts.email.accounts.tu-dresden.address;
+          user.email = "simon.bruder@mailbox.tu-dresden.de";
         };
       })
       [

users/simon/modules/mail/default.nix

@@ -1,7 +1,12 @@
+{ pkgs, ... }:
 {
   imports = [
-    ./accounts.nix
+    #./accounts.nix
-    ./aerc
+    #./aerc
-    ./notmuch.nix
+    #./notmuch.nix
+  ];
+
+  home.packages = with pkgs; [
+    thunderbird
   ];
 }