Added CreateDirectory function to service/fs.cpp, and in Archive.

src/core/file_sys/archive_sdmc.cpp

@@ -57,6 +57,15 @@ std::unique_ptr<File> Archive_SDMC::OpenFile(const std::string& path, const Mode
     return std::unique_ptr<File>(file);
 }
 
+/**
+ * Create a directory specified by its path
+ * @param path Path relative to the archive
+ * @return Whether the directory could be created
+ */
+bool Archive_SDMC::CreateDirectory(const std::string& path) const {
+    return FileUtil::CreateDir(GetMountPoint() + path);
+}
+
 /**
  * Open a directory specified by its path
  * @param path Path relative to the archive