Added support for loading .optoctreepatc (sic) files.

Discord shortens uploaded file extensions to 13 characters, for some reason. This cuts off the final `h` character in an `.optoctreepatch` file, making it `optoctreepatc`.

src/FileLoading.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 
 namespace TerrainPatcher
 {
@@ -18,11 +19,13 @@ private static string[] GetPatchFiles()
         {
             string searchDir = Directory.GetParent(Constants.MOD_DIR).FullName;
 
-            string[] paths = Directory.GetFiles(
-                searchDir,
-                $"*{Constants.PATCH_EXTENSION}",
-                SearchOption.AllDirectories
-            );
+            string[] paths = Constants.PATCH_EXTENSIONS
+                .SelectMany(ext => Directory.GetFiles(
+                    searchDir,
+                    $"*.{ext}",
+                    SearchOption.AllDirectories
+                ))
+                .ToArray();
 
             return SortFiles(paths, GetLoadOrder());
 

src/Mod.cs

@@ -69,11 +69,15 @@ internal bool IncludePatches
 
     internal static class Constants
     {
-        // The current version number of the optoctreepatch format.
+        // The current version number of the patch format.
         internal const uint PATCH_VERSION = 0;
 
-        // The current file extension for the optoctreepatch format.
-        internal static readonly string PATCH_EXTENSION = ".optoctreepatch";
+        // All valid file extensions for the patch format.
+        internal static readonly string[] PATCH_EXTENSIONS =
+        {
+            "optoctreepatch",
+            "optoctreepatc", // Discord shortens uploaded file extensions to 13 characters.
+        };
 
         // The current version number of the game's batch format.
         internal const uint BATCH_VERSION = 4;