Convert methods to use keyword arguments instead of options Hashes

[acant]

After support for Ruby 3.0 is added, it is probably time to convert all the methods to use keyword arguments instead of options Hashes.

This change was announced back in 2019, and released in Ruby 3.0:

• https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/

I have already made a small internal change to account for keyword arguments in Ruby 3.0.

Here is some other documentation about keyword arguments from Thoughbot:

• https://thoughtbot.com/blog/ruby-2-keyword-arguments