Functionalities for testing purposes or of less usage should be deprecated

[wehs7661]

Here we list functionalities in the package that will be removed/deprecated soon:

• [ ] The scheme of multiple swaps
• [ ] The RMSE cutoff for weight combination
• [ ] The option final for the YAML parameterw_combine

The documentation will also be updated accordingly.

[wehs7661]

Closing the issue since we decided to leave more detailed notes in PR #31, which covers a broader range of refactoring weight combination schemes.