Configs in one folder

[virio-andreyana]

Closes #632

Changes proposed in this Pull Request

• Move all config files (including test config files) to a config folder name "configs"
• changes the Snakemake file, so that the config.yaml would be located inside the configs folder
• since each results folder already contain the config.yaml file, syncignore-receive is updated to ignore the configs folder

Checklist

• I tested my contribution locally and it seems to work fine.
• Changes in configuration options are added in all of config.default.yaml.
• Changes in configuration options are also documented in doc/configtables/*.csv.
• A release note doc/release_notes.rst is added.

[virio-andreyana]

Note that all of the CI don't work because the directory of the file 'test/config.electricity.yaml' have been moved.

[fneum]

Note that all of the CI don't work because the directory of the file 'test/config.electricity.yaml' have been moved.

Could you also adapt the references to config files in CI and documentation? Then CI should work.

[fneum]

Some items in the documentation will also be affected by this moving of config files.