Update ROADMAP with no-reference-import TSLint equivalent

[KingDarBoja]

What were you trying to do?

I successfully ran the tslint-to-eslint-config but noticed there was a rule that hasn't an equivalent:

tslint-to-eslint-config does not know the ESLint equivalent for TSLint's "no-reference-import"

This rule is defined at tslint:recommended, which was present on the extends array on my tslint.json file.

"no-reference-import": true

I think there is a rule already handling this one as discussed at #625.

However, would be great to update the roadmap with this rule equivalent and same applies for other rules.

Cheers!

[bradzacher]

cc @JoshuaKGoldberg