chore: housekeeping — linter & formatter setup

Add .prettierrc.json, .markdownlint.json, .yamllint.yaml, .gitattributes
Run CSharpier, Prettier and markdownlint across the entire codebase.
No logic changes — formatting, using order and line endings only.

HellionChat/Commands.cs

@@ -16,15 +16,22 @@ internal sealed class Commands : IDisposable
     {
         foreach (var wrapper in Registered.Values)
         {
-            Plugin.CommandManager.AddHandler(wrapper.Name, new CommandInfo(Invoke)
-            {
-                HelpMessage = wrapper.Description ?? string.Empty,
-                ShowInHelp = wrapper.ShowInHelp,
-            });
+            Plugin.CommandManager.AddHandler(
+                wrapper.Name,
+                new CommandInfo(Invoke)
+                {
+                    HelpMessage = wrapper.Description ?? string.Empty,
+                    ShowInHelp = wrapper.ShowInHelp,
+                }
+            );
         }
     }
 
-    internal CommandWrapper Register(string name, string? description = null, bool? showInHelp = null)
+    internal CommandWrapper Register(
+        string name,
+        string? description = null,
+        bool? showInHelp = null
+    )
     {
         if (Registered.TryGetValue(name, out var wrapper))
         {