As a software engineer
I want support for MKD and PUT FTP commands
So that I can add files and directories to an archive with an FTP client

Given there are a list of FTP functions in crates/unftp_sbe_anttp/src/lib.rs
When integrating with AntTP over protobuf
Then implement PUT function using protobuf RPC calls as defined in /proto/public_archive.proto
And use UpdatePublicArchive RPC to add the file or directory
And don't implement other endpoints yet in this task

Given the address of the archive changes after it has been modified
When a file is added to the archive
Then store the new address as the archive being used for all FTP commands
And then the user experience will seem like the archive was just updated
And continue to use store-type = memory

Given AntTP (and Autonomi) don't support creating empty directories in archives
When a new directory is created using MKD
Then create a hidden (.metadata) file in the target directory using UpdatePublicArchive
And then the directory will appear to be created and other files can then be added by a client 

Given testing would improve quality
When adding the PUT command
Then update the unit tests and integration tests to reflect the new DEL command

Implementation Notes

- Place any unit tests at the bottom of the same file as the associated production code
- Increment patch version of anttp package in Cargo.toml
- Create a copy of this issue description and save to /spec using the name of this issue as the filename (with lower underscore case, starting with the 5 char padded issue number, e.g. 00001_issue_title.txt)
- Implement basic unit tests