Add Niri, a scrolling tiling window manager.

modules/home/wms/niri/rules/default.nix

@@ -0,0 +1,42 @@
+{ pkgs, config, ... }:
+{
+  config.home.niri.settings.rules = pkgs.writeText "rules" ''
+    // Browsers
+    window-rule {
+      match app-id="MainBrowser"
+      open-on-workspace "${config.ws.w1}"
+    }
+    window-rule {
+      match app-id="AltBrowser"
+      open-on-workspace "${config.ws.w1a}"
+    }
+    
+    // Communication
+    window-rule {
+      match app-id="MiscBrowser"
+      match app-id="vesktop"
+      block-out-from "screencast"
+      open-on-workspace "${config.ws.w7}"
+    }
+    window-rule {
+      match app-id="org.gnome.Fractal"
+      match app-id="org.telegram.desktop"
+      open-on-workspace "${config.ws.w8}"
+    }
+    window-rule {
+      match app-id="thunderbird"
+      open-maximized true
+      open-on-workspace "${config.ws.w9}"
+    }
+
+    // Etc
+    window-rule {
+      match app-id="looking-glass-client"
+      open-on-workspace "${config.ws.w2a}"
+    }
+    window-rule {
+      match app-id="com.obsproject.Studio"
+      open-on-workspace "${config.ws.w4a}"
+    }
+  '';
+}