Update and rename default-issue.md to task-issue.md

Changes proposed in this pull request:

Related issues

Submitter checklist

• Added logging is not capturing sensitive data and is set to an appropriate level (DEBUG vs INFO etc)
• Updated relevant documentation (README, ADRs, explainers, diagrams)

Security considerations

• No security considerations, just changing the issue template

[Note the any security considerations here, or make note of why there are none]