github: use an obviously old version of ripgrep in issue template

This should hopefully avoid confusion where the use of the version
number in the issue template isn't mistaken for the implication that the
version must therefore be recent.

Ref #2824

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -24,7 +24,7 @@ body:
  attributes:
  label: What version of ripgrep are you using?
  description: Enter the output of `rg --version`.
- placeholder: ex. ripgrep 13.0.0
+ placeholder: ex. ripgrep 0.2.1
  validations:
  required: true