nix: package with flakes; simplify devshell

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ia37044debea91a1db3d944a0c74f66356a6a6964

nix/package.nix

@@ -0,0 +1,30 @@
+{
+  lib,
+  rustPlatform,
+}:
+rustPlatform.buildRustPackage {
+  pname = "lychee";
+  version = "1.0.0";
+
+  src = let
+    fs = lib.fileset;
+    s = ../.;
+  in
+    fs.toSource {
+      root = s;
+      fileset = fs.unions [
+        (s + /crates)
+        (s + /Cargo.lock)
+        (s + /Cargo.toml)
+      ];
+    };
+
+  cargoLock.lockFile = ../Cargo.lock;
+  enableParallelBuilding = true;
+
+  meta = {
+    description = "Simple, opinionated image viewer for Wayland";
+    maintainers = with lib.maintainers; [NotAShelf];
+    license = lib.licenses.mpl20;
+  };
+}