docs: Update issue/PR templates

[steve-nester-uk]

Goal

Changeset

Tests

Discussion

Alternative Approaches

Outstanding Questions

Linked issues

Review

For the submitter, initial self-review:

• [ ] Commented on code changes inline explain the reasoning behind the approach
• [ ] Reviewed the test cases added for completeness and possible points for discussion
• [ ] A changelog entry was added for the goal of this pull request
• [ ] Check the scope of the changeset - is everything in the diff required for the pull request?
• This pull request is ready for:
  • [ ] Initial review of the intended approach, not yet feature complete
  • [ ] Structural review of the classes, functions, and properties modified
  • [ ] Final review

For the pull request reviewer(s), this changeset has been reviewed for:

• [ ] Consistency across platforms for structures or concepts added or modified
• [ ] Consistency between the changeset and the goal stated above
• [ ] Internal consistency with the rest of the library - is there any overlap between existing interfaces and any which have been added?
• [ ] Usage friction - is the proposed change in usage cumbersome or complicated?
• [ ] Performance and complexity - are there any cases of unexpected O(n^3) when iterating, recursing, flat mapping, etc?
• [ ] Concurrency concerns - if components are accessed asynchronously, what issues will arise
• [ ] Thoroughness of added tests and any missing edge cases
• [ ] Idiomatic use of the language