Adding a new rule: Underscore numeric literals.

[nexsja]

Description

Added a new rule for numeric literals: numeric literals should be chunked in 3s and delimited with a _.

Checklist

• tests are added
• CHANGELOG.md is updated

[romtsn]

Thanks for the PR, but I think we cannot accept it as part of the standard ruleset (at best - experimental), as no such convention exists in https://kotlinlang.org/docs/coding-conventions.html. The rule also can be considered highly opinionated - we will discuss whether we introduce a new contrib ruleset, if yes, this can definitely be part of it

[nexsja]

Fair enough, thanks for the feedback. :)

If you do decide to add this to any other ruleset - I don't mind finishing up whatever's necessary. Thanks! :)

[shashachu]

@nexsja we've considered having some sort of repo or ruleset with community-contributed rules, but it doesn't actually make a lot of sense right now to host them all into a single ruleset, since it's very unlikely any developer would want all of them. We would need to introduce the idea of code style sets (#548) in order for something like this to make sense. But thanks for the contribution! I encourage you to host this rule in your own repo. :)