Investigate merging notices

[egiurleo]

In #87, tslint-to-eslint-config began logging rule notices, but there wasn't any infrastructure that took into account the possibility of having to merge notices. I have updated line 81 in convertRules.ts to just merge the two notice arrays, but we should investigate creating a merger for rule notices.

[JoshuaKGoldberg]

I'm curious if there are any opinions on the best way to do this. One suggestion that pops to mind is to change rule mergers to have 1-2 members: merger.ruleArguments and an optional merger.notices.

[JoshuaKGoldberg]

On second thought, rule notices are pretty much always simple strings such as "Class expressions will no longer be ignored.". I think it's fine to just deduplicate strings and return the result:

Array.from(new Set(ruleOne.notices, ruleTwo.notices))

FYI @egiurleo - now accepting PRs! 😉

[egiurleo]

@JoshuaKGoldberg ;D ;D

[egiurleo]

I will look at this this week!

[JoshuaKGoldberg]

Released in 0.2.4! ✨