Add an explanation for the missing Applicative instances for monad transformers

[kubukoz]

Closes #2272.

Just a few lines to start with, hope you have some feedback on what else I can mention/what can be reworded :)

[codecov-io]

Codecov Report

Merging #2277 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2277   +/-   ##
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  Coverage   95.12%   95.12%           
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  Files         364      364           
  Lines        6707     6707           
  Branches      285      301   +16     
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  Hits         6380     6380           
  Misses        327      327

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[kailuowang]

Thanks!

[LukaJCB]

I like it, but can we extract a bit from the issue you linked, I feel like just linking to an issue will cause people to have to wade through a bunch of discussion instead of getting to the actual point. You know what I mean? 🤔

[kubukoz]

Sure, I'll look for something that can be there instead of the link.

[kubukoz]

Can we just drop the link? The potential inconsistency is already mentioned. WDYT?

[LukaJCB]

I think that might be more confusing, then it'd just say "This is inconsistent" without naming a good reason.

[LukaJCB]

Maybe add the counter example noted here? #1106 (comment)

Of course would need porting to EitherT or OptionT instead. :)

[easel]

LGTM. I agree it would be better to extract the content from the linked ticket.

[kubukoz]

@easel I haven't had much time to work on this recently, but I'll surely extract something before I consider this good to merge :P

[kubukoz]

@LukaJCB as part of this week's goal to finish up all open OSS PRs, I updated this one - please take a look :)

[kubukoz]

@kailuowang FYI

[kailuowang]

Thanks very much @kubukoz !