tiny: add module (#2735)

Added module for tiny, a TUI IRC client written in Rust. Thanks to @ratsclub for helping me write my first Nix module!

modules/programs/tiny.nix

@@ -0,0 +1,65 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  cfg = config.programs.tiny;
+  format = pkgs.formats.yaml { };
+  configDir = if pkgs.stdenv.isDarwin then
+    "Library/Application Support/tiny"
+  else
+    "${config.xdg.configHome}/tiny";
+in {
+  meta.maintainers = [ hm.maintainers.kmaasrud ];
+
+  options = {
+    programs.tiny = {
+      enable = mkEnableOption "tiny, a TUI IRC client written in Rust";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.tiny;
+        defaultText = literalExpression "pkgs.tiny";
+        description = "The <command>tiny</command> package to install.";
+      };
+
+      settings = mkOption {
+        type = format.type;
+        default = { };
+        defaultText = literalExpression "{ }";
+        example = literalExpression ''
+          {
+            servers = [
+              { 
+                addr = "irc.libera.chat"; 
+                port = 6697; 
+                tls = true;
+                realname = "John Doe";
+                nicks = [ "tinyuser" ];
+              }
+            ];
+            defaults = {
+              nicks = [ "tinyuser" ];
+              realname = "John Doe";
+              join = [];
+              tls = true;
+            };
+          };
+        '';
+        description = ''
+          Configuration written to
+          <filename>$XDG_CONFIG_HOME/tiny/config.yml</filename>. See
+          <link xlink:href="https://github.com/osa1/tiny/blob/master/crates/tiny/config.yml"/>
+          for the default configuration.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    home.packages = [ cfg.package ];
+
+    home.file."${configDir}/config.yml" = mkIf (cfg.settings != { }) {
+      source = format.generate "tiny-config" cfg.settings;
+    };
+  };
+}