docs: Increase buffer size in CopyFile function for vastly improved file copy efficiency

Author: MetalHexx

Source/Teensy/FileTransfer.ino

@@ -424,7 +424,7 @@ FLASHMEM bool CopyFile(const char* sourcePath, const char* destinationPath, FS&
     }
     while (sourceFile.available())
     {
-        uint8_t buf[64];
+        uint8_t buf[4096];
         size_t len = sourceFile.read(buf, sizeof(buf));
         destinationFile.write(buf, len);
     }