High-level website upload using CLI

[PaulLeCam]

Leveraging feeds the CLI could provide a command that would implement the following flow:

1. Generate a key pair or use a provided private key (provided directly, from an env variable or file)
2. Create a feed manifest based on inputs (at least the website name or the manifest hash)
3. Upload folder with defaultpath set to index.html

So the command could be something like erebos website:upload ./dist --name=my-website --key-file=./key

Another website:create command could be used to create the key pair and write it to the file for example depending on the provided flags.