[ReadME Example] - include file extension to save it properly

[mcpeblocker]

Example was not working: files were being saved without their extension according to the example shown for DiskStorage

[LinusU]

Sorry for the late reply.

This is being done intentionally since it could be a security vulnerability to blindly use the extension provided by the client.

The client is free to send whatever extension it wants, and web-servers (or even just browsing the files with a file manager) could treat the file differently depending on the extension.