some rules are set to error, but without precising what they should be

[ntraut]

some rules like semi and comma-dangle are set to error, but it is not specified if they should be always or never, so the default rule is kept unless the rule is modified by another extension.
is this really what we want?
in the case we want to let the default, why set the level to error?

[ntraut]

the default option for semi is always, and the default option for comma-dangle is never. setting them to error ensure that the default rules are observed.

note that those stylistic rules are now deprecated in order to be replaced by the ones from @stylistic/eslint-plugin-js, at some point we may want to do the migration: https://eslint.style/guide/migration