update config from ini to yml

[hboisgon]

Issue addressed

Fixes #207

Explanation

Update hydromt config files from ini to yaml. Also updated the tests and docs.

Checklist

• Updated tests or added new tests
• Branch is up to date with main
• Tests & pre-commit hooks pass
• Updated documentation if needed

[hboisgon]

I removed the _archive folder. There were still some old docs files on wflow build/update etc. I don't think we need to track this so I decided to remove rather than update the files.

[dalmijn]

Everything checks out.

There seems to be a docs bug, but I made a separate issue for that #233

Also, the docstrings for the base 'Model' object methods 'update' and 'build' should be updated at some point.