patterns: Added Minecraft LCE ARC file format (#307)

* Create arc.hexpat

* add test file

* mention arc

* abide by contributing.md

* use virtual filesystem

* brainfart

* ifdefs to fix github actions moment #2

patterns/arc.hexpat

@@ -0,0 +1,26 @@
+#pragma author DexrnZacAttack
+#pragma description Minecraft LCE ARC File
+#pragma endian big
+
+import std.string;
+#ifdef __IMHEX__
+    import hex.core;
+#endif
+
+struct Table {
+    u16 nameSize;
+    char fileName[nameSize];
+    u32 offset;
+    u32 size;
+    u8 file[size] @ offset;
+    #ifdef __IMHEX__
+        hex::core::add_virtual_file(fileName, file);
+    #endif
+} [[name(std::string::to_string(fileName))]];
+
+struct ARC {
+    u32 count;
+    Table table[count];
+};
+
+ARC arc @ 0x00;