Add command to initialize the conf directory

[n-dusan]

stelae command should initialize the archive conf directory.

Steps:

• Create .stelae directory
• Create config.toml
• Add keystores

[renatav]

After having some discussion regarding TAF and Stelae with @dgreisen and @n-dusan, we concluded that TAF should not enforce such conventions. We can add a command to TAF which is flexible enough so that we can create everything listed here given the appropriate input parameters and Stelae will call it