Add bad example for BigDecimalWithNumericArgument

[lucasocon]

This PR adds the bad example in documentation for Performance/BigDecimalWithNumericArgument
Ref: https://docs.rubocop.org/rubocop-performance/cops_performance.html#performancebigdecimalwithnumericargument

---

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.

[koic]

Thanks for opening the PR. docs/modules/ROOT/pages/cops_performance.adoc is a generated file. Can you update the following file.

--- a/docs/modules/ROOT/pages/cops_performance.adoc
+++ b/docs/modules/ROOT/pages/cops_performance.adoc
@@ -46,20 +46,14 @@ This cop identifies places where numeric argument to BigDecimal should be
 converted to string. Initializing from String is faster
 than from Numeric for BigDecimal.

+# bad
 BigDecimal(1, 2)
 BigDecimal(1.2, 3, exception: true)

-  # good
+# good
 BigDecimal('1', 2)
 BigDecimal('1.2', 3, exception: true)

-=== Examples
-
-[source,ruby]
-----
-# bad
-----
-
 == Performance/BindCall

 NOTE: Required Ruby version: 2.7

https://github.com/rubocop-hq/rubocop-performance/blob/v1.7.0/lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb

And can you generate the doc using bundle exec rake generate_cops_documentation?

[lucasocon]

Hey, @koic I updated the file where the documentation is generated and generated the doc.
Let me know what do you think.

[koic]

Perfect! Thanks!