Display version with cop added when pending cops warning

[koic]

Follow up of #7757 (comment).

When warning about a pending cop, this PR displays the version with the cop added.

Before

% rubocop
The following cops were added to RuboCop, but are not configured. Please
set Enabled to either `true` or `false` in your `.rubocop.yml` file:
 - Style/HashEachMethods
 - Style/HashTransformKeys
 - Style/HashTransformValues

After

% rubocop
The following cops were added to RuboCop, but are not configured. Please
set Enabled to either `true` or `false` in your `.rubocop.yml` file:
 - Style/HashEachMethods (0.80)
 - Style/HashTransformKeys (0.80)
 - Style/HashTransformValues (0.80)
For more information: https://docs.rubocop.org/en/latest/versioning/

---

Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Run bundle exec rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[pocke]

It looks a good improvement!

By the way, recently I've got a feedback about the feature from @znz.
He said it would be better if it displays the configurations. For example:

$ rubocop
The following cops were added to RuboCop, but are not configured. Please
set Enabled to either `true` or `false` in your `.rubocop.yml` file:
Style/HashEachMethods:
 VersionAdded: 0.80
 # Enabled: true/false # Confiure it!
Style/HashTransformKeys:
 VersionAdded: 0.80
 # Enabled: true/false # Confiure it!
Style/HashTransformValues:
 VersionAdded: 0.80
 # Enabled: true/false # Confiure it!

I think it is reasonable because the users can configure the new cops easier.
But I concern that it will be too long.
What do you think?

[bbatsov]

• Style/HashEachMethods cop added by 0.80

I think a better format would be "Cop (added in version)".

Might also be a good idea to add a link to the manual (https://docs.rubocop.org/en/latest/versioning/) at the end of the message, as it seems it confused some users.

I'd add to this page an example message and probably some configuration snippet (as suggested by @pocke), so it's easier for users to figure out what how to deal with the message.

[koic]

@bbatsov @pocke Thanks for the feedback.

I think a better format would be "Cop (added in version)".

Might also be a good idea to add a link to the manual (https://docs.rubocop.org/en/latest/versioning/) at the end of the message, as it seems it confused some users.

I updated the warning message and the versioning manual.

[bbatsov]

Great work! 🙇

[koic]

Thanks!