…ors [ci skip]`migrations_paths` option was added to migration generator, withchangelog entry, inrails#33760.Also `migrations_paths` option was added to model generator, withchangelog entry, inrails#33994.Then `migrations_paths` was renamed to `database` and aliased as `db`inrails#34021, and was added new changelog entry.I think we should edit existed changelog entries instead adding newabout changing the name of the option from `migrations_paths` to `database`since Rails 6.0 hasn't been released yet, and since It might confusereaders of the changelog file in case if they've read changelog enty aboutadding `migrations_paths` option but haven't read the entry aboutchange the name of that option to `database`.@eileencodes,@gmcgibbon,@rafaelfranca Does it make sense?

Thor automatically adds `-` if aliases do not start with `-`.https://github.com/erikhuda/thor/blob/0879c1773d188902d54f95174f33961ac33111f8/lib/thor/parser/options.rb#L53But Thor follows a convention of one-dash-one-letter options.So, even if `-` is added to `db`, it does not work.https://github.com/erikhuda/thor/blob/0879c1773d188902d54f95174f33961ac33111f8/lib/thor/parser/options.rb#L4Follow uprails#34021.

* [Add migrations_paths option to migration generator](rails/rails#33760)* [Add migrations_paths option to model generator](rails/rails#33994)* [Refactor migrations_path command option to database](rails/rails#34021)