Update issue templates

[Andrew Coughtrie (andrewcoughtrie)]

Description

Some changes to the format and wording of the issue templates to make them clearer and more useful. The type label probably only works for the main Met Office repos not peoples forks, when looking at the preview it claims there is an error, I suspect this is because the Issue type is in preview and not available to the general public yet.

Linked issues

Closes # (issue)

Developer tags

Type of change

• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• This change requires a documentation update.

How has this been tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration.

• New tests have been added.
• Tests have been modified to accommodate this change.
• GitHub workflows have been changed or added.

Checklist:

• The change has been checked for design compliance by an experienced SSE
  
• My code follows the style guidelines of this project.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes, for both debug and optimised builds.
• No AI tools have been used in the creation of this change.

Reasoning on why any of the above boxes have not been checked

Review Checks (To be filled in by the reviewer/s)

• Has the developer completed the appropriate sections above?
• Is the change compliant with LFRic Core principles?
• Is the testing coverage sufficient?
• Have any technical debt workarounds identified had issues opened and interested parties notified?

[James Bruten (james-bruten-mo)]

This looks fine to me, cheers