Improve configuration initialization

[Mpdreamz]

Updates the init-config target to validate the passed --git-ref is actually the one that is checked out.

docs-assembler repo init-config --git-ref 2c41839a928e4fbb1f838ec46a05c81cbe346144

If you just want the latest/edge you can omit --git-ref

docs-assembler repo init-config

Then you can force init as a configuration source.

docs-assembler repo clone-all --config-source init
docs-assembler repo repo-all --config-source init

If the application folder init-config writes to is not available both of these will exit with an error code.

info ::e.d.c.tionFileProvider:: ConfigurationSource.Init: git ref '2c41839a928e4fbb1f838ec46a05c81cbe346144', in /Users/mpdreamz/Library/Application Support/elastic/docs-builder/config-clone/config
info ::e.d.t.f.foLoggerFilter:: Configuration source: Init
info ::e.d.t.f.foLoggerFilter:: Configuration source git reference: 2c41839a928e4fbb1f838ec46a05c81cbe346144

If --config-source is not provided it will default to ConfigurationSource.Local if config exists in the pwd, this is the default during development.

Otherwise ConfigurationSource.Embedded will use the configuration files embedded in the binary.

[cotti]

Just a note on RepositoryCommands, otherwise LGTM!

[cotti]

This is unreachable due to the earlier if on gitref that exits with an error, isn't it?