Improved contributors guide

[hkershaw-brown]

Description:

Improved contributors guide

• More friendly tone
• More concrete explanation of what you can do to contribute and how.
• remove quick-start for developers because it is out-dated, also not sure developers should be quick starting.
• removed separate requesting-features-reporting-bugs.rst since this is covered in contributors guide.

Fixes issue

fixes #813

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Documentation changes needed?

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

Tests

Build documentation locally

Checklist for merging

• Updated changelog entry
• Documentation updated
• Update conf.py

Checklist for release

• Merge into main
• Create release from the main branch with appropriate tag
• Delete feature-branch

Testing Datasets

• Dataset needed for testing available upon request
• Dataset download instructions included
• No dataset needed

[mgharamti]

Looks good to me. I've added a few changes for clarity. Otherwise, I think this is also good to go.