asciinema: Add module to configure package

Enabling and defining minimal config file example;

```nix
{
  programs.asciinema = {
    enable = true;
    settings = {
      session.idle_time_limit = 2;
    };
  };
}
```

...  _Should_ result in output `~/.config/asciinema/config.toml` of;

```toml
[session]
idle_time_limit = 2
```

Co-authored-by: Austin Horstman <khaneliman12@gmail.com>

tests/modules/programs/asciinema/default.nix

@@ -0,0 +1,3 @@
+{
+  asciinema-settings = ./settings.nix;
+}

tests/modules/programs/asciinema/settings.nix

@@ -0,0 +1,60 @@
+{
+  programs.asciinema = {
+    enable = true;
+
+    settings = {
+      server.url = "https://asciinema.example.com";
+
+      session = {
+        command = "/run/current-system/sw/bin/bash -l";
+        capture_input = true;
+        capture_env = "SHELL,TERM,USER";
+        idle_time_limit = 2;
+        pause_key = "^p";
+        add_marker_key = "^x";
+        prefix_key = "^a";
+      };
+
+      playback = {
+        speed = 2;
+        pause_key = "^p";
+        step_key = "s";
+        next_marker_key = "m";
+      };
+
+      notifications = {
+        enable = false;
+        command = ''tmux display-message "$TEXT"'';
+      };
+    };
+  };
+
+  ## TODO: check that `command` quote escaping doesn't break things
+  nmt.script = ''
+    assertFileExists home-files/.config/asciinema/config.toml
+    assertFileContent home-files/.config/asciinema/config.toml \
+    ${builtins.toFile "expected.asciinema_config.toml" ''
+      [notifications]
+      command = "tmux display-message \"$TEXT\""
+      enable = false
+
+      [playback]
+      next_marker_key = "m"
+      pause_key = "^p"
+      speed = 2
+      step_key = "s"
+
+      [server]
+      url = "https://asciinema.example.com"
+
+      [session]
+      add_marker_key = "^x"
+      capture_env = "SHELL,TERM,USER"
+      capture_input = true
+      command = "/run/current-system/sw/bin/bash -l"
+      idle_time_limit = 2
+      pause_key = "^p"
+      prefix_key = "^a"
+    ''}
+  '';
+}