Add overlay for mautrix-discord

Signed-off-by: Magic_RB <magic_rb@redalder.org>

flake.nix

@@ -55,6 +55,7 @@
         overlays/emacs-master-nativecomp
         overlays/zfs-relmount
         overlays/ical2org.nix
+        overlays/mautrix-discord.nix
       ];
 
       flake.nixosModules = {

overlays/mautrix-discord.nix

@@ -0,0 +1,39 @@
+# SPDX-FileCopyrightText: 2022 Richard Brežák <richard@brezak.sk>
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+{ inputs, ... }:
+{
+  flake.overlays.mautrix-discord =
+    final: prev:
+    let
+      inherit (prev.lib)
+        singleton;
+    in
+    {
+      mautrix-discord =
+        prev.buildGoModule rec {
+          pname = "mautrix-discord";
+          version = "0.3.0";
+
+          src = prev.fetchFromGitHub {
+            owner = "mautrix";
+            repo = "discord";
+            rev = "v${version}";
+            hash = "sha256-Qlok8LnnuJYCmkDssyNRfrHSdBNi5J40cXJHX7xa4fI=";
+          };
+
+          buildInputs = singleton prev.olm;
+
+          vendorSha256 = "sha256-OqMa4hpJLQRID8QxxX++lyFy/6b3Rg9GeQ7Qe+dsIkY=";
+
+          doCheck = false;
+
+          meta = with prev.lib; {
+            homepage = "https://github.com/tulir/mautrix-whatsapp";
+            description = "Matrix <-> Discord hybrid puppeting/relaybot bridge";
+            license = licenses.agpl3Plus;
+            maintainers = with maintainers; [ ];
+          };
+        };
+    };
+}