Documentation and MR template updates relating to light mode

[helenb]

Link to Ticket

Description of Changes Made

• Update MR template to add a note about checking both dark and light mode (I have also updated the list on the Monday ticket template)
• Update the docs to add details about the dark and light mode functionality
• Added clarifying comments to the high contrast light and dark mode mixins to explain that these do not relate to the dark and light mode functionality

How to Test

• Run mkdcos serve
• View the new docs at http://0.0.0.0:8001/custom-features/modes/

Screenshots

Expand to see more

MR Checklist

• Add a description of your pull request and instructions for the reviewer to verify your work.
• If your pull request is for a specific ticket, link to it in the description.
• Stay on point and keep it small so the merge request can be easily reviewed.
• Tests and linting passes.

Unit tests

• Added
• Not required

Documentation

• Updated build docs
• Updated editor guidelines (See https://intranet.torchbox.com/torchbox-com-project-docs for the private link, for Torchbox employees only)
• Updated field spec (See https://intranet.torchbox.com/torchbox-com-project-docs for the private link, for Torchbox employees only)
• Not required

Browser testing

• I have tested in the following browsers and environments (edit the list as required)
  • Latest version of Chrome on mac
  • Latest version of Firefox on mac
  • Latest version of Safari on mac
  • Safari on last two versions of iOS
  • Chrome on last two versions of Android
• Not required

Data protection

• Not relevant
• This adds new sources of PII and documents it and modifies Birdbath processors accordingly

Accessibility

• Automated WCAG 2.1 tests pass
• HTML validation passes
• Manual WCAG 2.1 tests completed
• I have tested in a screen reader
• I have tested in high-contrast mode
• Any animations removed for prefers-reduced-motion
• Not required

Sustainability

• Images are optimised and lazy-loading used where appropriate
• SVGs have been optimised
• Perfomance and transfer of data considered
• If JavaScript is needed alternatives have been considered
• Not required

Pattern library

• The pattern library component for this template displays correctly, and does not break parent templates
• The styleguide is updated if relevant
• Changes are not relevant the pattern library

[helenb]

@RealOrangeOne feel free to improve this wording!